


Thermocline

by J_Baillier



Series: Thermocline [1]
Category: Sherlock (TV), Sherlock Holmes & Related Fandoms
Genre: Academia, Adventure, Alternate Universe, Angst, Consent is Sexy, Convention-challenging romance, Guatemalan coast, Hurt/Comfort, John Watson is a Good Doctor, John likes consent very much, Lousy pickup lines, M/M, Malta, Marine archaeology, Please note the trigger warning at the start of chapter 1, Scuba Diving, Sherlock Holmes is a Bit Not Good, Sherlock doesn't play well with others, Sherlock is asexual, Slow Burn, Technical diving, Tropical wankage, Underwater Peril, and John is a horndog, relationship drama, wreck diving
Language: English
Status: Completed
Published: 2020-01-01
Updated: 2020-02-08
Packaged: 2021-02-27 14:28:31
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 14
Words: 83,557
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/22068541
Author URL: https://archiveofourown.org/users/J_Baillier/pseuds/J_Baillier
Summary: John "Five Oceans" Watson — technical dive instructor, dive accident analyst and weapon of mass seduction — meets recluse professor of maritime archaeology Holmes. As they head out to a remote archipelago off the coast of Guatemala to study and film its shipwrecks for a documentary, will sparks fly or fizzle out?
Relationships: Greg Lestrade & John Watson, Sherlock Holmes/John Watson, Working relationships between various OCs, one more relationship to be added later, see trigger warning for details
Series: Thermocline [1]
Series URL: https://archiveofourown.org/series/1635769
Comments: 1021
Kudos: 624
Collections: Johnlock in the great outdoors





	1. The Expat

**Author's Note:**

> [[an index and guide to all my Sherlock stories](https://archiveofourown.org/works/25011148)]

**Notes for the Chapter:**

> [Trigger warnings for this story](https://jbaillier.tumblr.com/post/190273060460/trigger-warnings-for-thermocline). I decided not to put them in the tags to prevent revealing the plot too much. The link contains MASSIVE SPOILERS. If clicking the link doesn't work, copypaste https://jbaillier.tumblr.com/post/190273060460/trigger-warnings-for-thermocline into your browser.

John leans back in his chair and lifts his bare heels onto the balcony railing. The air-conditioning in his modest flat has been broken for two days and, in accordance to finest Mediterranean tradition, the repairman will show up when he can be bothered, regardless of what time has been agreed upon. But John isn't troubled by this; if he minded the less neurotic way of life and the embrace of the scorching sun, he wouldn't have expatriated to Malta. There's also the world-class diving, of course, the cheap costs of living, and the hordes of female British tourists looking to let loose on a cheap package holiday.

It's very close to paradise, really.

In three hours, he's due for a job: the owner of a local dive centre, whose regular tech diving instructor is on sick leave, had called John last night to ask whether he could take two clients to the HMS Southwold wreck off Marsaskala. A type II Hunt-class Destroyer for the Royal Navy in World War II, it sunk after hitting a mine. The explosion killed five, split the hull and plunged the ship down to the sea bottom. With a sandy bottom, good visibility and rich fish life, it's a fantastic dive. The problem for most holiday divers is that the deepest parts lie at 70 metres — too deep to be dived with just air in the tanks and without special gear. That makes it too demanding a site to be dived without special training even if the diver doesn't intend penetrating into the preserved sections.

John had taken his gear to the dive centre last night, did the gas blending, talked to the clients who'd also popped in to drop off their gear to make sure they truly had the skills and experience required for the endeavour. He had left booking sea transport to this morning which had been a mistake; it had taken him forty minutes of calling around to find a charter boat for the dive; it's high season, so such services are in high demand. He's yearning for a cold beer, but drinking before a dive is not on.

Drinking _after_ one, now that is a different matter... Marsaskala — a sleepy resort-less town on the southern coast of the main island — only has a few decent establishments and John will have to drive the clients back to their hotel in Sliema after the dive, anyway. He decides to round his usual haunts tonight right here in St Julians. The younger, more adventurous crowds usually flock at the Rumrunner around midnight, whereas the Chalice gathers a more refined early-night clientele. Not all of his decent shirts can be in the wash pile, can they…?

His phone chirps to life in the kitchen, and he drops his feet from the railing and hurries through the clattering mosquito curtain on the balcony door made of bamboo pieces to get to it.

Caller ID says _'Bridgette of the BBC_ ', and John cracks a grin. Bridgette Stevens is his insider contact and a fan-fucking-tastic lay. Gorgeous tits and no strings attached—especially when John gets to slip a pair of them offher. With Bridgette, things are never awkward or complicated. Perhaps he might even call her a friend.

"Hell _o_ ," he greets, "Someone's desperate for me again, are they?"

"Hey, John. Is the weather as terrible there as it is here in London?"

"If we're talking endless sunshine, temperatures in the thirties and just a ripple on the sea then yes, absolutely despicable. I don't understand why anyone comes here voluntarily," he chuckles.

"Then I couldn't possibly wrench you away from all that," she teases.

"What have you got?" John asks. "If it's another project on the effects of urban pollution on coral growth, you can bin that idea right now. I want to see something other than used condoms and rat skeletons. That Langkawi thing sucked."

"I know. They ended up shelving it, said it wasn't up to BBC standards."

John isn't surprised. The director had been an inexperienced idiot who had no idea how much time and effort setting up underwater cinematography entailed. His previous documentaries had been about skateboarding.

"So, what's this you've got for me, then?" John prompts.

"The Entierro Islands off the coast of Guatemala. A three-episode series on maritime archaeology aiming for prime time. The Guatemalan army is decommissioning their base on the islands and, since nobody expects such a craggy spot so far from the coast and the sea currents there are unpredictable, it's a graveyard of wrecks. There are some warships, but we're also expecting really old stuff according to the maps the army's been willing to declassify. There's something about the place that shipworms don't like; even some wooden structures are preserved. A university research group, backed by us, will be the first civilian group allowed to dive there, and that's what we're filming. You interested?"

"Depends on the role. Not prancing my arse in front of the cameras any more than I have to. And I won't work with a director who can't tell apart a garden sprinkler from a regulator."

"You'd be the expedition physician. Also, they need you as a dive technician, maybe even tec instructor and of course one of the divers. They have tec-trained divers in the group, and a local dive instructor has been commissioned, but they need someone _good_.There's no telling how challenging it'll get. I instantly thought of you."

"I'm touched."

"You'd be on a boat for five weeks."

"Long expedition. Is that why they want a medic onboard?"

"New company policy. If the BBC is the main backer and there's no access to a hospital within an hour's boat trip or a helicopter evacuation isn't possible within forty-five, a physician must be a part of the crew."

"I like that logic." John knows he'll mostly be dealing with wounds, sunburn, upset stomach and other small things, and an expedition doctor's double role will increase his pay. "How deep are the dives?"

"Most wrecks are likely to be between thirty and eighty metres. Could be some they haven't found yet that are deeper, but there's a huge underwater mountain—seamount, if you will, since it's too big to be called a pinnacle—on top of which most of the wrecks lie. The deepest bits of it are at around ninety metres."

"Trimix, then, if they want anything close to a decent bottom time for the wrecks." A gas mixture consisting of oxygen, helium and nitrogen, Trimix is one of the most common blends used for technical — or _tec_ — diving. The term refers to acquiring and using more advanced techniques and skills than those taught to hobbyist divers, blended gases and complex speciality equipment usually designed or at least customised by the diver to achieve greater depths and longer bottom times. Helium allows the lowering of the oxygen percentage in the gas mix, increasing the divers' safety along with their potential operating depth: oxygen becomes toxic to the central nervous system at depth. The twenty-one percent contained in regular air inhaled at great depth for long enough will lead to vertigo, seizures and very likely, death. Forty metres is usually considered the deepest one should consider going without blended gases.

"I don't know about that," Bridgette comments in a disinterested tone to John's choice of gas. She had only done a beginner open water diver course, so she isn't familiar with the principles of tec diving beyond what John has rambled to her over drinks. He had met her right before she'd enrolled on her holiday PADI diving course: she'd been sent to have a word with him before the first lessons because of her asthma. In the following days, they'd spotted each other a couple of times on the Marsalforn beach boulevard on Gozo where the dive centre was. A smaller Maltese island famed for its diving, central Gozo was where John had his first flat after moving to the country. After he had struck up a conversation with Bridgette one evening as they watched the sunset from the small walk-bridge on the boulevard, the evening had progressed and ended in a mutually _very_ satisfactory manner.

"So, which twenty-something celebrity have you picked to be the host of this documentary? You need someone who looks good in a wetsuit. Attenborough hardly qualifies."

"David doesn't even do archaeology," Bridgette laughs. "I'm afraid there's going to be slim pickings for you on this expedition; just blokes unless they find a female captain; we haven't secured a boat yet."

Thankfully, John is very much a proponent of gender equality when it comes to the sex he's having. Not that Bridgette knows this; John knows better than to kiss and tell. "Who's in the camera team, then?"

"Lestrade's the director, and he's actually going to be having a go at hosting, though we'll try to use the expedition's head scientist for that as much as we can. And, there's a new guy behind the camera, Anderson."

"Hm." John hasn't heard of him, nor does he particularly care who's operating the zoom as long as they stay out of his finning path. Lestrade's an old friend from a few past projects; it'll be nice to work with him again. "Which university?" Probably some backwater place if they can't fund such an expedition themselves.

"Oxford. The professor's our head scientist, and we've got several PhD students joining the expedition, too."

John whistles. The Oxford Centre for Maritime Archaeology is one of the world's leading units in the field. The professor is probably some old geezer — the Attenborough of maritime archaeology. _Shame._ John would have enjoyed working with some young, hopefully attractive up-and-comer scientist. Maybe there's hope yet if those PhD students prove… interesting.

John hears the rustling of papers, after which Bridgette lists two maritime archaeology PhD students, one marine biologist, one local diving specialist, and the head scientist—a _Professor Holmes_.

"Never heard of him." It's strange that he hasn't since he watches every BBC documentary that has anything to do with the underwater world.

"We've been trying to land him for years, but he's not been keen at all. Still isn't; told us in no uncertain terms that if he could have raised the money some other way, he wouldn't be letting us on the boat."

"Sounds like a charmer."

John's current work mostly involves teaching the occasional technical diving course at one of the local British-owned diving schools when he isn't taking clients of various such establishments out for dives. Sometimes he also gets commissioned to join demanding salvage and rescue dives. When he's not diving, his job also entails telling fifty-something, morbidly obese British tourists with heart conditions that they should skip taking a beginners' scuba diving course and stick to eating ice cream in the shade. The dive schools send people to him when they tick a box in the 'yes' bracket of the questionnaires every hopeful diver is given to fill out before being kitted out. People could lie on those forms, of course, but if something bad happened, their insurance wouldn't cover the costs of the treatment or even the cost of hauling the corpse back home. Regular travel insurance doesn't tend to cover scuba diving any more than it does mountain climbing or bungee jumping; one needs to have additional insurance cover for such sports, and respectable dive establishments won't let anyone on their guided dives or courses without proof of it.

The health screening part is the only bit about commercial leisure diving courses John thinks works relatively well; the rest of what new divers should learn has been toned down to a frighteningly bare-bones version of safety skills. For this reason, many dive professionals not getting their paychecks from these organisations tend to joke that the abbreviation PADI, the name of the most widespread fun diving training organisation, really stands for _Pay And Die Immediately_. On occasion, John gets contacted by British insurance companies and DAN—a global non-profit that grants divers specialised insurance—to investigate accidents and cases of decompression sickness. Malta is perhaps the best place in the world to have a diving-related mishap: there are many hyperbaric treatment chambers, good helicopter coverage and lots of highly trained diving physicians working for the islands' hospitals.

Several dive centres have offered John a job with a monthly salary, but he likes being a freelancer. A free agent. If he wanted a 9–5 job five days a week, he would have stayed in the UK.

"The Entierros are being hailed as the Galapagos Islands of sea archaeology," Bridgette declares. "I think you'd be in for a treat." Bridgette entices.

"Sounds like it, yeah."

"Can I count you in? Or are you getting too cosy on Malta?" She teases.

"When do we leave?"

**Notes for the Chapter:**

> While tec diving is beyond my training I am an avid recreational scuba diver, and Malta is my regular summertime haunt. In fact, these first chapters were drafted in the small fishing village of Marsalforn in Gozo on a dive holiday. I've done [a Tumblr post about my practical research for this fic](https://jbaillier.tumblr.com/post/189973981720/nobody-gets-to-tell-me-i-dont-take-my-fic). Here are some [beautiful photos of the HMS Southwold](https://divewise.com.mt/hms-southwold).
> 
> I've had the privilege of working with several betas as I developed this story, particularly with the aim of being respectful towards readers who may identify with Sherlock's sexual orientation. Each individual is unique, of course, and Sherlock's experiences, identity, preferences and dislikes should naturally not be considered a generalisation of all. It's all a beautiful spectrum, and our archaeology professor will give John a lot to think about and a massive learning experience in this context.


	2. Five Oceans (And One Sea)

Two months later, John walks out of the elevators on the entrance floor of the three-star resort the BBC had picked for their last night on solid land. The Luna Pacífica is described online as 'down-to-earth' and its best days have clearly passed but the pool is big and clean, rooms specious and John has certainly seen worse.

He had arrived in town four hours ago, and after a rush job of a shower and change he didn't feel jet-lagged enough just to crash in his room. He spots a copy of the Times on the lobby bar counter and commandeers one of the chairs. An order of tea arrives promptly.

The Port of San Jose in Col el Progreso has no airfield, so private cars had been arranged to transport the team from Guatemala City to the coast. John's flight had arrived two hours after the BBC camera crew's and three hours before the Oxford lot's car. He hasn't caught a glimpse of Lestrade or his colleagues yet but it hardly matters. _There will be plenty of time to catch up on the boat._ What he does want to see more than his old friend is the arrival of the academics. He puts down the paper and shifts a bit in his chair to see better as three cars from the same rental agency as his own had been park in front of the revolving doors.

The first to walk in is a tall man with curly hair styled within an inch of its life. He is dressed and groomed impeccably even though he must have just sat for an ungodly number of hours in a tin can in the sky. Judging by his age, John assumes he is one of the PhD students, but the strange thing is that nobody else exits the car besides him and the driver. The man leaves all his bags, save for one that looks like it contains a laptop, to be dealt with by the rest of the team.

John's eyes trail the man as he walks to the reception desk without noticing him seated at the bar. Wearing a midnight blue suit, his posture is regal, and he carries his tall form with a dancer's grace. Eyes hidden behind designer shades, he would look at home at a photo shoot, or the trading floor of a City broker firm. Yet, there is something… striking about him, something that tells John he isn't quite as simple to categorise as one might think from a single glance.

John licks his lips. _He's a handsome bugger, isn't he?_ Those lush curls would undoubtedly feel nice to dig fingers into, and John has a thing for what looks like a runner's or swimmer's form: tightly packed, lean and proportionate muscles. They'd have a bit of a height difference to John's disadvantage, but his confidence wouldn't take much of a beating from such a thing. _Doesn't matter when you're not standing up_. There couldn't be that much of an age difference, either. _About five years younger?_

The man wastes no time with the check-in; he is scribbling fast on the registration form and, judging by the receptionist's waning smile, her warm welcome had not been appreciated.

John turns to look the other way when he hears the revolving door again. An even younger man with blond hair cut in a pompadour fade, dressed in worn red chinos and a rumpled white T-shirt is looking much more like someone who'd been on a long flight. He drags a heavy suitcase in and stops just inside the lobby. He is soon joined by a burly, Scandinavian-looking man of equal age with a black, haggard beard and a worn band T-shirt singing the praises of something called Dimmu Borgir.

"Think Professor Holmes will get all our room keys?" The beard asks.

The blond gives him a grimace. "I very much doubt it."

John does a double take. _That can't be the professor, can it? Maybe that's his son who's one of the students?_

John can now only see the back of the tall man. His suit sits as though it had been sewn onto his lithe form — clearly an expensive, bespoke one beyond the means of a postgrad student, unless they have a sizeable trust fund. Add to that the fact that he'd had a car all to himself…

 _Professor Holmes_ , John marvels to himself. _Really not what I expected._ Nothing like anyone would expect, really, of the director of perhaps the world's most prestigious institute in the field.

Holmes snatches a room key card from the receptionist, picks up his laptop bag and marches off in the direction of the elevators.

The blond student shrugs and goes to drag in more bags from outside. A bellhop walks out of the elevator just as Holmes strides in, and hurries after the younger man to help him. Black beard has gone to the reception desk, and soon the rest of what John assumes is the archaeology team flocks into the foyer.

John decides against introducing himself to them now; the Oxford crew are probably antsy to get into their rooms and have a rest. Besides, they had all been informed by a very formally worded email from the professor that introductions would be made at an _assembly_ on the evening of their arrival. Their boat — more of a yacht, really, judging by the pictures emailed to John — is due to arrive in the morning to stock up on supplies, fill the tanks and pick them up at Marina Pez Vela.

John turns back to his tea which is now only lukewarm. Instead of continuing with the Times, he digs out his mobile. The hotel WiFi requires no password, and soon he's scrolling through the Oxford Centre for Marine Archaeology's website. He'd skimmed through the website before but had not opened the staff roster pages. Now, he clicks on the "Academic and Senior Research Staff" subsection, and what he has just observed is water-tightly confirmed: the man the visuals of whom he's just appreciated is none other than Professor Sherlock Holmes, Director of the Centre.

Although he is not the grey-bearded relic John had expected, his list of publications must already number in the hundreds. On the Centre's website he is introduced as having a particular interest in warships as manifestations of overall coastal war strategy in different eras as well as the use of shipwrecks in the mapping of ancient trade and conquest routes. An introductory text from a major archaeology conference website explains that his research approach combines _in situ_ examination underwater, sophisticated multibeam echo sounder technology and the use of archived historical sourced texts. The Centre's website tells John that Holmes had done his PhD on identifying shipwreck sites in difficult-to-navigate Irish coastal water using data from something called the Irish Bathymetric Survey. As part of his that project, Holmes had discovered and dived La Juliana, one of three Spanish Armada ships wrecked off the west coast in 1588. The discovery had been reported widely even outside scientific circles and lauded as a very significant find in shedding light on King Philip II of Spain's attempt to overthrow England's Protestant Queen Elizabeth I.

John is doubly impressed. He's a mere hobbyist when it comes to submerged archaeology, but he can tell very few postgrad students would make such ground-breaking discoveries. _Looks like Professor Holmes will make an interesting introduction in many ways._

_____________

Half an hour before the assembly time, John heads back down to the lobby bar and is delighted to see that Greg Lestrade has had the same idea. Soon, he and Greg's team are sharing a table in the corner just below a small, grainy TV blaring out a football match.

Greg looks well; he's sporting a great tan and he's let his salt-and-pepper hair grow a bit longer and wilder.

"So, how's our Bridgette?" John asks. "Still as lovely as ever?"

"Don't you start," Greg chortles. "She's engaged."

"Never stopped her before. She's a free spirit, like me."

"There's the Five Oceans Watson we know and love," Greg announces and nudges Anderson for attention, nearly spilling the man's pina colada which he's trying loudly to suck into his gills through a straw.

"And one sea," John reminds them, forefinger sticking pointedly up from the hand that's holding his drink. "The Mediterranean's a perfectly decent puddle." He stares down into his pint after taking a swig. "Half of this must be water. We should get out of this bloody tourist bar, find some real stuff." In cheaper resorts offering all-inclusive drink packages, the cocktails and sometimes even beer is watered down to increase profit margins.

"Not before we've had our _assembly_ ," Anderson grimaces. “Couldn’t we have had it tomorrow morning? We’re all sweaty and knackered from the flight."

John rolls his eyes in sympathy. The evening is still young but getting old fast while they sit around waiting for this pow-wow the Oxford team has insisted on. He won't be seeing solid land in a month and is planning to make the best of this free night in a passable resort.

"Anybody seen Holmes?" He asks. "I assume he'll be the one running the meeting."

Greg nods towards the opposite end of the bar. John has to get out of his seat to see around a column but finally, he spots Holmes who has set up shop at the end of the bar counter. The bartender doesn't seem happy about his piles of folders, his laptop and a long stretch of what look like continuous-roll fax printouts snaking all the way to the floor. He has ditched his jacket but kept his tight trousers, his leather Oxfords and the white dress shirt he'd been wearing earlier. It's so tight that the buttons strain a little as he leans down to pick up a piece of paper from the floor. He then grabs a napkin, dips it in his glass of water and cleans the fingers which had touched the floor.

"Who the hell even uses a fax machine that old anymore?" John wonders out loud, turning back to face his table company.

"The Guatemalan army," Greg replies. "Those are old frogman training reports he's got, detailing the wrecks they had found on training dives. They had a fax and phone connection between the few habited islands."

Anderson pipes up. He has a nasal voice John wouldn't want to listen to for long. "Looking forward to working with you, John. Greg here has been singing your praises."

"All lies, I'm sure," John quips. He checks the watch-sized dive computer on his wrist. "Ten minutes left to wait. Night's getting old, and I need to find someone to soothe the sorrow of losing Bridgette to the throes of holy matrimony," he pretends to complain with a grin.

"Still in fine form, then?" Greg asks. "You know I can't be your wingman anymore; Molly hates it. You're on your own for this one, mate." Molly is Greg's girlfriend, a well-known wildlife photographer.

"Only brought you along out of pity," John teases. "Besides, I like a challenge. Such as Posh Boy over there. Looking so damned prim even in this heat. Wouldn't be surprised if he likes it a bit rough."

In that strange way that people just _know_ when you're looking at them, Holmes raises his head from his papers and looks straight at John. His expression is that of a Sphinx: completely unreadable. Their eyes meet and John raises his pint which elicits little reaction besides the man's piercing eyes narrow a little before his focus shifts back to whatever is on his laptop screen.

"I hope _Holmes_ is not your only game plan for tonight," Greg says. "I know a couple of guys who went to uni with him and did postgrad in the same research group. They say he never goes for that sort of thing. And, a friend was on the last doc expedition he shared a boat with and said that he didn't have any other contacts on his phone except for his brother."

John waves a confidently dismissive a hand at Greg. "He's just waiting for Mr Right Trouser Leg. Just look at him; why would he drag his paperwork down here if it wasn't a smokescreen? I know the type; shows up in a bar pretending to be there for anything but a hook-up with half a section of Tesco hair product section in their head, all waiting to be courted. He was checking me out just now." He may be exaggerating some; the look Holmes has given him didn't seem to signify any kind of invitation.

"He's just creepy like that," Anderson pipes in. "He checks _everybody_ out. Reads them. _Deduces_ them. Nobody likes him."

John slams his empty pint determinedly on the counter. "Well, you're not helping his case."

 _Holmes can't be that bad_. He's not the first snooty academic John has dealt with. Some of them are _animals_ in the sack.

Anderson glances at his watch, announces that it's time for the team assembly so they drag themselves into the conference room.

To everyone's surprise, Professor Holmes doesn't even show up. Instead, the blond PhD student starts reading out loud from what appears to be an email from the man.

"Professor Holmes thanks you all for your dedication to this expedition — unless that dedication proves to be lacking. He wants me to introduce everyone––" the young man glances around the room. "So, we've got me, hi, I'm Andrew — God, I suddenly feel like I'm in an AA meeting."

There's a chuckle from everyone that seems to lessen the awkwardness at least a little. "So, Andrew Hatfield's the name, I'm a PhD student the prof supervises, and I also double as his assistant. The other PhD candidate over there––" he points at the bearded man John had already seen who has removed the peaked cap he'd had on earlier and unearthed a black, thin ponytail. His shorts look like they might disintegrate at any moment and he has the same model of dive computer on his wrist as John. "––Is Mo. Morten, if you ask the tax man. Morten Lund. He's Swedish but don't hold it against him. He will dive in anything, anytime, and I've seen a video of him drinking schnapps _under_ the ice."

Morten gives everyone a wave. Anderson and John wave back but mostly, there are polite nods. John decides he likes the young scientist immediately; he knows plenty of these hippie types, some of them practically diving nomads who have been drawn to a scientific career mostly because it allows for plenty of dive time.

"We've then got Senior Lecturer Joseph Pellier from the Oxford marine biology unit." A Frenchman with an unflattering crewcut in his chestnut hair, a stiffly pressed white shirt and baby blue linen trousers, he gives everyone an elegant nod. John wonders how many minutes it will take for those posh clothes to get mucky once they get to work.

"That's everybody I know, so the rest I'll read out loud from Professor Holmes' email. Jose-Perry is the name of our captain; we'll meet him tomorrow; he and the boat are a sublet from Blue O Two, which I'm told is a premier organiser of diving liveaboards."

Blue O Two holidays cost a pretty penny but the luxury yachts they use have bartenders and air conditioning and other stuff that shoestring budget outfits only have wet dreams of. Dive staff jobs on their boats are a sought-after commodity, but the clients also expect a high level of personalised service. John prefers a different demographic in his clientele — one that isn't too fancy to fix their own gear and take off their own fins after a dive.

"Joseph Pellier and Jose-Perry… We need to come up with a nickname for either so they don't get mixed up," Greg comments, shaking his head. Jose- _Perry_?" He repeats. "Where's he from?"

"I know him," an older woman standing in the doorway says with very heavily Spanish-influenced English. "He's Dominican, his mother loved Perry Mason."

Another chuckle.

"You must be Mariza, our chef?" Andrew asks the woman.

"Chef, cleaning lady, laundry person, everything. Anything you need, tell me, but I cannot do any diving things. We have four other crew members, they are on boat now with Jose-Perry."

"From the BBC we have joining us Gregory Lestrade," Andrew continues reading.

"Just Greg, please."

"And Philip Anderson, who's going to be shooting all the hopefully nice underwater footage."

Anderson flashes a bright smile.

Andrew then introduces another cameraman, Terry Bodington, who will handle interviews and other above-water shoots and act as Greg's production assistant.

"Our local dive specialist is Dionisio Coron, who has thirty years of experience of Guatemalan diving. Professor Holmes is expressing his scepticism regarding Coron's usefulness, since _nobody_ has really dived this archipelago. We'll meet him tomorrow; his daughter's wedding is today so he couldn't make it to this meeting."

John always appreciates local knowledge and seeks it actively whenever he's diving in a new area. Even though the islands are a virgin location for commercial or scientific diving, the more expert divers they've got on this trip, the better.

"It's a shame Professor Holmes wouldn't join us; I would have liked to hear his diving qualifications," John pipes in before Andrew gets to continue.

The young man leafs through the thick wad of printed pages. "There's an FAQ at the end where that question's covered. He says he has done the PADI Tec 100 CCR course two years ago and clocked 60 hours of Trimix use since. Altogether, his logbooks contain 258 dives in varying ocean environments, including deep wreck penetration."

John refrains from commenting on how well he thinks a PADI tec course serves the purposes of a serious scientific deep wreck expedition, but at least Holmes has clocked a serious amount of experience afterwards.

"Professor Holmes mentions you last — John Watson, isn't it?" Andrew asks.

John gives a nod. "Yeah."

"John will be our dive technician, head diving consultant and expedition physician. According to professor Holmes' summary, he has…" Andrew rustles his prints around, "…satisfactory qualifications for this expedition."

John can't help snorting. His expertise being evaluated by a relative tec rookie such as Holmes is almost funny, and the professor's phrasing had made him sound almost underwhelming. In reality, John has done over a thousand dives with hypoxic Heliox and Trimix gas blends, including plunges down to a hundred and thirty metres. He has trained dozens of tec instructors and about a hundred tec divers in total. Once he got a foot in the door with the BBC and consequently Discovery Channel, he's had the pleasure of being a support diver or tech specialist for a number of their filmed expeditions, some of them featuring very risky and ambitious dives. These have included exploring the legendary wreck of the Andrea Doria eight years ago when the tec scene was still small; it had been one of the highlights of his career. Known as the Mount Everest of wreck diving, the Italian ocean liner collided with another ship and sank, taking 46 people with it. John has a photo of himself from one of the dives where he's holding the brittle, silt-covered skull of one of the victims. He'd hung the picture — a cut-out from National Geographic magazine — on his wall at home.

His most challenging dive so far has been a German U-boat off the coast of Jersey where the mixture of cold water and dangerously strong currents at ninety metres had put him further beyond his comfort zone than anything else in his career. In addition to pioneering dives into several newly founded wrecks he has also done the better-known and more accessible tec classics, including Scotland's Scapa Flow's and Truk Lagoon in Micronesia—both graveyards of warships.

"Hi, everyone," he says to the set of expectant faces.

"You'll do the gas blending as well, then?" Morten asks.

"That's what I was told would be a part of my duties, yes," John replies promptly.

The simplest blended diving gas — Nitrox, consisting of air with extra oxygen added in — is used even by recreational holiday divers with relatively little training. As a technical diving instructor with extended training, John has the requisite skills to select and blend suitable mixes of not just oxygen and air but also helium to be used in long, deep dives which, if done on air, would either allow only for a few minutes of time on the bottom, or lead to severe injury or death.

As depth increases, oxygen becomes a poison to the central nervous system while also being vital to life. The nitrogen, which the atmosphere and thus air-filled dive tanks contain, becomes an anaesthetic gas at depth, leading to a loss of the sense of danger and logical thinking. That is why technical divers add helium into the mix — it allows for a lower oxygen percentage to be used and lessens the risks of developing nitrogen narcosis. The downside is that diving on mixed gases require a diver to carry several different gas tanks on a single dive and to switch between them at different stages. Hundred percent oxygen can be used near the surface to hasten the exit of nitrogen bubbles from the body, but if a diver accidentally inhales from that tank at depth, it can kill instantly.

There are also many other risks associated with just diving very deep or penetrating wrecks and caves, which tend to be the motivation for tech divers to select their dive sites; blended gases allow diving as deep as several hundred metres. Such diving requires solid basic diving skills, serious training, expensive and complicated equipment and dedication.

"So, what I've gathered is the divers are me, Dionisio, Joseph, Holmes, Anderson and Morten — Greg, I assume you still refuse to put on a wetsuit?" John teases his friend.

"Nope, and not just because they look like whole-body condoms. I'll be doing my narrating and producing safely from the surface, thank you."

"Andrew, you don't dive, then?" Anderson asks.

"I'm mostly just along to be Professor Holmes' assistant; because I have a messed-up eardrum. Never even could do the Open Water Course as much as I wanted to."

"Shit luck, mate," John says, and means it. _A marine archaeologist who can't dive is a genuinely sad concept_. He knows not all do, but it seems counter-intuitive not to go see submerged sights for themselves. "I have Morten's, Anderson's and Holmes' past diving experience info but what about you, Joseph?"

"I am a Divemaster, so cannot join for technical dive," Joseph replies in a lilting, heavily accented English.

"That's fine. You'll still be able to handle more challenging conditions and be able to survey the sunlight zone marine life."

Joseph grins. "Yes, yes, exactly. Very exciting."

Andrew leafs through the prints again. "There was something… Ah, right, yes, something the Professor instructed me to say. He is _of the opinion_ that when it comes to the non-scientific personnel, especially the diving specialists who he finds to be _a most tedious collective of small-minded adrenaline junkies_ , the same applies to them as it applies to children: they are best seen and not heard."

"That's pretty solid rubbish, coming from someone who dives as well," John scoffs.

"That's in his Q&A, too," Andrew sighs. "He says that for him, diving is a tool, not a hobby. He sees it as no different than taking a jeep to a distant dig in the desert and will not condone wasting time on diving-related frivolity when there's work to be done."

"Lucky us, stuck with such a bundle of joy," Anderson grumbles in a low voice to Greg and John. "Well, _I_ for one, am going to make use of this opportunity. John, you up for some fun diving when we're not on duty?"

"Absolutely. Assuming we don't have too much of a nitrogen load after the expedition dives."

Andrew clears his throat. "So, the plans is as follows, according to Professor Holmes: there are three areas which have been surveyed by the Guatemalan Navy and guaranteed to be free of sea mines. They are kindly letting us use their sonar maps and dive training logs in which wreck data has been recorded. There are eight potentially interesting wrecks within those regions. We shall pick three of the most historically significant for further study while allowing Doctor Pellier to study the flora, fauna and geography of the submerged mountain. You should prepare for depths between twenty and a hundred metres."

While Holmes is technically qualified for it, a hundred metres is a risky challenge for his level of experience. "Realistic depths will depend on conditions below," John can't resist pointing out, "and the performance of the group on easier dives."

Andrew nods. "Sure. You'll have to… negotiate all that with Professor Holmes when the time comes."

"I don't negotiate about safety. I doubt Dionisio will, either."

Andrew bites his lip and folds his printouts. "Yeah, I'm sure you can… suss all that out."

  
______________

"Why the hell did Holmes even come to the bar, then, if he wasn't going to run the assembly?" John wonders out loud as they file out of the room.

"Beats me," Greg replies.

"I told you, he's _studying us_ ," Anderson says conspiratorially.

"I overheard Andrew and Morten talking earlier; they're saying that Holmes prefers to run his department via email, and he intimidates people into not talking to him unless they really have to."

"He doesn't look that scary," John says. "If he came to the bar, that means he wants company. Even if he looks like he doesn't know how to go about getting some. Doesn't he look kind of stressed to you, in need of a bit of a break?"

"And you're going to help him with that, then?" Greg asks, smirking.

"I thought it was part of my dive specialist duties to ensure that all penetration of dark spaces happens safely," John tells him conspiratorially and parts with Greg and Anderson who are headed back to the table they'd held earlier.

John heads to the smaller bar counter in the lobby, instead, and orders two shots of tequila. Instead of re-joining Anderson and Greg, he goes to sit in the far left of the bar counter where the professor is still frowning over what look like sea navigation charts.

"Evening," John says with a smirk. He hopes his new, white polo shirt isn't too sweaty and crumpled. At least his new plaid shorts look very decent, even paired with flipflops.

He's delighted to be able to observe Holmes from up close. His tailored trousers are hugging his tight yet plump arse; the silhouette of it is nicely visible since his chair does not have a backrest. Once again, John pities his straining shirt buttons and wants to save them by popping them open. _Oh, yes_.

He moves one seat to the right and plonks the shot glasses next to Holmes' laptop.

The man shifts it slightly away. "John Watson, I presume?"

John extends a hand. Holmes takes it, then coils his lithe, elegant fingers around John's and gives them a tight, brief, efficient squeeze before withdrawing and turning back to his computer screen.

"Sorry to have missed you at the assembly."

"I assumed Andrew could handle conveying my instructions." Holmes finishes typing up a sentence, then turns to look at John as though wondering why he's still there.

"Tequila?" John offers.

Holmes looks at the glass John has slid close to him as though he's being offered poison. "No, thank you. I never partake."

"Well, more partaking for me, then." John downs both shots and steals Holmes' napkin to dab his lips dry. "I hope you're not thinking of burying yourself under all this the whole night." John picks up a fax print which Holmes snatches away and places on the opposite side of his computer.

"I've been forced to set up shop here, since neither the air conditioning nor the Wi-Fi are working in my room, and they are taking an awfully long time to set up the suite I was promised as a replacement."

John whistles. "Suite, eh? Well, that's a silver lining," he says cheerily, leaning closer to Holmes. He's never been put off by people who play hard to get. He knows he can meet the challenge. "How about you finish up here, then we go test that suite of yours up? We could probably get them to throw in some champagne for the delay."

Holmes blinks. He doesn't look like he's pretending not to understand — he genuinely looks like he doesn't. " _We_? I wasn't informed we would have to share rooms. In fact, I explicitly told the BBC––"

John laughs. "Well, I _can_ stay the night afterwards, if that's what you like." _Though it's not really my style._

Now, Holmes finally seems to get his meaning. "I–– I'll have you know that I consider myself married to my work."

"Nothing wrong with having a little something on the side, is there? I'm sure your work won't divorce you."

"I'm saying _no_ , if that wasn't already clear."

John cocks his head, gives a lop-sided grin softened by the tequila. "Alright, alright, then. No harm done. Just asking. You know where to find me, if you change your mind."

He has never understood why some people are nervous or even scared to just go for it, to speak out about who they're interested in. _What's the worst that could happen?_ If the other person says no, then one just has to respect it, and be respectful of them afterwards. All there is to it.

John's train of thought is interrupted by Holmes' mobile ringing. He digs it out of his pocket, frowns at the number, then his eyes do a thing as he seems to realise who it is. The number is shown, but the phone's address book doesn't recognise it. John watches as a strange progression of emotions flits through the man's features. Surprise turns to alarm, then something resembling fear. Then, evasive determination as Holmes presses the rejection button and shoves the phone back into his pocket.

"Not going to answer, then?"

"Obviously not." The tone is cold, and John knows he has outstayed his welcome. After a no, one shouldn't become a nuisance. Plenty of other fish in the sea. _But fewer on this ship of fools._

John slides off his barstool, planning on getting himself a pint and returning to the table where Greg is animatedly explaining something to Anderson who has succumbed to the seductive taste of yet another pina colada. John has been hungover on them too many times to ever want to even see another coconut in his life.

He gets only two steps away from the bar counter before Holmes clears his throat loudly behind him.

John turns — a bit slowly. _Should probably slow down on the booze_. He's usually not such a lightweight; maybe he is a bit jetlagged, after all.

"What's up?" He asks Holmes.

"Out of curiosity: that was your best line, then? Something you assumed would instantly sell me the idea of spending the night with you? Tell me, _John Watson_ , why is it that the likes of you never evolve beyond fulfilling the whims of your basest instincts? Does it really not occur to you that others may not think like you, or consider you something they would instantly want to pounce on? Is this–– this _thing_ that you do––"

"Thing?"

"Bedding everything that moves."

" _Bedding_? I'm sorry, have we gone back to 1895?"

"Your behaviour suggests that either you're overcompensating for the size of your genitalia or for the fact that your discharge from the army was only barely honourable, seeing as you contracted the injury which ended your combat diver career while drunk. So, which is it?"

John's jaw drops. _How the hell does Holmes know about that?_ " I was saving a mate," he says angrily. _Not that I owe you an explanation._ He saved a mate, got a bum knee and they told him he didn't fulfil the strict health criteria anymore. The knee only troubles him occasionally, now; nothing a rest day can't fix. He's over what happened; without his discharge he may have stayed in the army and missed out on a lot of the commercially funded adventures he's had. It's fine, but who would enjoy negative life events being thrown in their face?

"Ah, yes. This mate being an equally inebriated pride and joy of Her Majesty's Armed Services who fell into a pond with old construction material sticking out of the bottom."

"It's none of your fucking business. Seriously; what's with the lecture? All I did was admire what I was seeing, and you're biting my head off for it? You said no, I respected that, and now you're dragging old shit you're not even supposed to know about into the mix? Was it some ex who tried to call and wrecked your mood and now you're taking it out on me?"

Holmes huffs, gathers his things and prepares to storm off, but his laptop slides off the top of the papers on his lap. John grabs it before it falls on the floor.

"Thank you," Holmes mutters, and heads for the reception desk.

John shakes his head and returns to Greg and Anderson.

Soon, they can hear a very angry baritone from the reception desk threatening litigation if a room is not made available _post haste_.

"No luck, then?" Greg asks John.

"Luck had little to do with that," John shoots back. "Another round?"

  
  


**Notes for the Chapter:**

> Don't worry — we shall not be getting into the minutiae of gas laws and all that; you now know enough about tec diving and gas blending for the purposes of our adventure. I'm Nitrox-certified but not a tec diver so I have no experience of being on Heliox or Trimix. I have been narced once, tho, meaning nitrogen narcosis. Felt great at the time, chillin' with a barracuda on a beautiful sandy-bottomed area listening — and ignoring — the beeping warnings of my dive computer. You only realise after ascending a bit how dangerously carefree nitrogen makes you.
> 
> Didn't they used to teach us at school that there are four oceans? Yes, but in 2000 the International Hydrographic Organization divided the World Ocean into five principal oceanic areas delimited by continents and oceanographic features. They are: 1. The Pacific Ocean, 2. The Atlantic Ocean, 3. The Indian Ocean, 4. The Arctic Ocean and 5. The Southern Ocean. While John might have received his nickname at a time when the standard number was four, I like the idea of being oceanographically hip in this fic. If I wanted to be more historical, I would have of course named John _Seven Seas Watson_ , but that was a bit too… um… piratey for the purposes of this story.
> 
> [Blue O Two](https://blueotwo.com) is a splendid company and I like a bit of luxury on my holidays so John should stop being snooty about all that. The boat in this story is based on the fleet's Blue Voyager, on which I've had the pleasure of exploring the Maldives on a liveaboard and will absolutely choose the company for my future adventures. A liveaboard means a diving holiday where your hotel is a floating one. All you do is dive and eat and sleep and lounge around enjoying the scenery.
> 
> Here's [a good list](http://divemagazine.co.uk/travel/6189-malta-wrecks) (with pictures) of Malta's wreck dives. As part of the research for this fic, I explored the interior of a splendid wreck: an East German Kondor I-class minesweeper by the name of Boltenhagen lying at the bottom of the strait between Malta's main islands. Here are two videos other divers have shot at the wreck: [video 1](https://www.youtube.com/watch?v=wkUXhBR0MKQ), [video 2](https://taucher.net/video-wrack_p29_ex_boltenhagen__cirkewwa-uaz2752).
> 
> Sherlock's PhD project was based on [this piece of Irish wreck news](https://www.nbc-2.com/story/29363545/400-year-old-spanish-shipwreck-found-off-ireland).
> 
> The [wreck of Andrea Doria](https://scubadiverlife.com/diving-the-andrea-doria/) has cost the lives of many divers, [some of them very experienced](https://www.boston.com/news/local-news/2017/08/02/the-lures-and-dangers-of-diving-to-the-andrea-doria). [Footage from diving the wreck](https://www.youtube.com/watch?v=3vHUccSxE_U).


	3. The First Plunge

John, standing on the pier, raises a hand to greet the staff as their boat glides towards the marina. He has to be mindful of the countless gear bags spread around as he walks to the edge to grab the rope thrown by a staff member.

They'd arrived at the pier an hour ago, and enjoyed some strong coffee sitting in the shade next to a kiosk close to the marina office. The occasional cloud has drifted by and occluded the sun, but mostly the skies are clear, the fresh air tastes of ozone and salt, and the wind is only the ghost of a breeze. Even though the proximity of the ocean makes the skin sticky and sweat is already beading at John's hairline because the weather is so hot and humid, what he smells and tastes and pulls into his lungs with every inhalation is flooding him with pleasant memories of past departures into adventure. It's not just the diving he loves: even just being on the ocean, watching the scenery or spotting birds as waves lap against the hull is a day well spent.

The staff files onto the pier, including the captain, and there's a round of handshakes.

John sits on a bollard pole to fire off a text to Bridgette to tease her about the weather in London. He doesn't have a lot of people to say farewell to before heading out. His sister wouldn't care; they haven't heard from each other in years, and their parents have passed away.

Holmes appears next to him, glancing down at John, who closes his phone and pockets it.

"The M/Y _Salaminia_. A respectable name," Holmes muses, shielding his eyes with the side of his palm as he squints at the boat.

John remembers from the emails that the name of the boat was supposed to be the "M/Y Blue Fantasy" since Blue O Two tends to name all of its vessels in such a fashion. He now spots that there are small hooks on the hull where the name is supposed to be, and the name _Salaminia_ is a sign hanging from them. It appears the captain has wanted to rename his pride and joy for this adventure temporarily.

"Why's that?" John asks, patting the rust flecks he'd got from the pole off his shorts.

Holmes gives him a most unimpressed look. "Two ships with a key role in the Peloponnesian War in the late 5th century BC, the Salaminia and the Paralos were the sacred triremes of the Athens navy."

"I guess I'm a little rusty on my triremes."

Holmes puts his sunglasses back on and retreats from the edge of the dock to find his bags. John takes a few steps back as well to avoid getting his toes crushed by the metal boarding plank being extended.

__________________

After depositing his bags into his cabin on the lower deck and his dive gear in the designated area at the bottom back of the boat, John walks through all of the vessel's four decks to get his bearings. Most of the basic cabins, including John's, are on the lower deck. Holmes had commandeered one of the more luxurious ones on the mid deck and Greg, as the producer, had been given the one opposite him. The Captain's cabin is close to the command bridge on the upper deck. The top deck consists only of a large sundeck, a part of which is covered. The bar on the upper deck has been reserved for the setting up and maintenance of camera gear while the mid deck salon and the open-air dinette on the same deck are for socialising.

Then, he returns to the mid deck and walks around it with the intention of grabbing a can of Pepsi from the fridge in the salon and settling into the open-air dinette area to enjoy the breeze. Now that they're moving, the sun's heat no longer feels so oppressive. The Guatemalan coast is just a green line in the horizon, now.

Once he has a cold drink on hand, he goes aft to watch the waves the boat is making and the coastline growing distant. He can't help his heart swelling at the sense of expectation, of the idea of where they are heading.

Someone has scotch-taped an army map of the Entierros on the wall just behind one of the dining tables. There are four major islands flanked by smaller ones. Isla Ruina is where the old army base is; no longer used for training, there is just a one-man outpost there, now, to monitor traffic in the area. Isla Fuego rises to an imposing 1200 metres since there is a dormant volcano in the middle. Isla Maria Santa Madre seems to have collected the greatest number of larger wrecks; it and Madre are the first of the islands visible to anyone approaching from the Central American coast. Between Isla Canoa and Isla Ruina is the middle of the sunken table mountain, and the area had been dubbed _The_ _Graveyard_ by the army divers due to the large number of wrecks in that concentrated area. There are two narrow straits dumping waters onto the submerged plateau, which may mean fierce currents.

 _No one has studied these wrecks before, and the islands have barely even been dived before_ , John marvels. Judging by the geography, the diving conditions may well be challenging, but he's never shied away from such things. Languid floating around looking at reef fishes is fine, but the true thrills lie elsewhere: inside sunken vessels, drift driving with _mola mola_ in Bali's Nusa Penida, encountering sharks and other large predators, night diving remote reefs as moonlight makes plankton sparkle.

  
___________________  
  
  


It's the hottest hour of the day, and John is glad for the shade of the gear storage and gas blending area on the back deck in front of the dive platform. He's very impressed with the boat's facilities: the gas blending membranes are all new, the deck squeaky clean and two narrow side walls are keeping the smell of exhaust fumes away; those should be prevented from getting into the tanks as they are filled. _Not nice, breathing in diesel fumes at forty fathoms deep_. The state of the boat is hardly surprising since this it belongs to Blue O Two.

He grabs a towel to rub residual grease off of his fingers; he'd been tightening the screws on his isolation manifold and making sure all the joints remain watertight. The manifold allows him to switch between tanks on deeper dives by closing and opening valves. On his longest, deepest tec dives, he has carried up to twelve different tanks, small bottles filled with pure oxygen for quick off-gassing close to the surface, heavy Trimix and Heliox tanks for the deep stages, and contingency tanks of air and blended gases.

John is itching to get in the water. According to Jose-Perry, there is plenty of time in Holmes' planned schedule for an en-route stop at a dive site called the Torres des Dientes. It has been featured in several trade magazine articles in the past couple of years, and if John still kept a bucket list as hobbyist divers do, Torres would be in the top three.

The site is a triad of pinnacles, where the tips of underwater mountains or cliffs reach close to the surface but don't breach it. Three hours away from the marina along their route, it should be the perfect spot to get their fins wet and to check everyone is up to their tasks before they spent a day and a half getting from there to the Entierros. _No point in making the trip only to notice that our gear isn't what it's supposed to be, or that someone's diving skills won't cut it_. No matter what training someone has undertaken and how many dives they've logged, John won't tec dive with anyone he hasn't done an easier dive with first, because he's seen enough seasoned veterans with lethally bad habits just waiting for their good luck to run out. _There are old divers and daring divers but very few daring, old divers._

Since they are so far away from the coastline, the pinnacles should make for a lovely afternoon dip with the possibility to spot larger pelagics which haunt deeper waters. Pinnacles are havens for smaller fish life, which attracts predators. Up north, off the coast of Baja California, the Guadalupe Island is a world-renowned site for seeing great white sharks. Currents are bound to be strong at such sites, but that hardly troubles John. _It'll be a good test for the team._ There will be a negative entry, meaning they'll have to jump in single-file and head-first and fin for their lives to get to the pinnacle before the currents sweep them off.

John fills eight double sets of twelve-litre tanks with air; it's always good to have a couple of spares in case there's a need for a rescue mission. Andrew doesn't dive, so that leaves John, Anderson, Holmes, Joseph, Dionisio and Morten. Three sets of regular scuba dive gear belonging to John, Dionisio and Anderson — who John had spoken with at lunch — have been prepared for action and placed on top of large plastic baskets on the dive deck; John should inform the rest that there's an opportunity for a dunk soon.

For that purpose, he climbs the stairs to the mid deck and enters the large salon there. Just as he's about to pull open the door that will let him into the open-air dinette in the back, it flies open, and the sight of an irritated Holmes fills the doorway.

"Why are we slowing down and veering off course?" He demands.

John isn't sure why the man is asking him; a quick glance over his shoulder tells him the dinette is as empty as the salon; perhaps all the others have retreated inside for a siesta. At lunch, John had okayed the afternoon dive plan with the captain and the camera crew, and he'd also talked to Andrew about it since Holmes hadn't shown up for the meal. The assistant had said he couldn't think of a reason why the dive en route wouldn't be a good idea. Andrew had obviously not presented the decision to the professor for some reason.

"We're stopping at the Torres Des Dientes for a check dive," John replies nonchalantly.

"For a _what_?"

"If I'm in charge of the diving, I need to know what — and who — I'm dealing with."

"I have provided my credentials which should be sufficient for anything we'll encounter. If you find those of the others lacking, why didn't you do your homework before the trip, demand changes in the team?"

"It's not the same reading someone's logbook and seeing them dive. Nobody would gamble a million on a racehorse without seeing them run, would they? Same diff." _We gamble with our lives if we choose the wrong partner_.

Holmes blinks. "That analogy is absurd. I haven't authorised wasting time on _fun diving_."

John shrugs. "Greg thinks we might get some nice footage from the site. It's a famous one."

"I'm not here to cater to the Great British television-viewing public; I'm here to do research. You're not authorised to make changes to the schedule or to discuss them with the captain."

 _God, he's a prick, isn't he?_ "Won't take us more than an hour and a half. Bottom time will be limited by depth and currents. Jose-Perry says we'll still make it to the Entierros within _your_ plan with a nice time margin to spare."

Holmes studies his expression. "You're _serious?_ This is some sort of a _sine qua non_ , then?"

"Yes."

"I'm not doing it. I understand if you want to check the other divers' skills––"

John squares his shoulders and leans closer to Holmes. "Let's make one thing clear. For me, there's no distinction between you and 'the other divers'. I don't do tec with anyone I haven't seen in action on an easier dive."

"I wasn't informed of this."

 _God, Bridgette, couldn't you have done your job of negotiating this shit a bit better?_ "Is it really such a nuisance, getting in the water for an hour? We're all sweaty, the weather's great, visibility should be fantastic at this time of the year according to Dionisio, and this is supposed to be the new Richelieu Rock."

"I don't know what that is. I don't indulge in recreational diving."

Richelieu Rock is a legendary Thailand dive site featuring exquisite reefs, soup-thick fish life and even whale sharks. It had been one of John's favourites before coral bleaching, and the 2004 tsunami wrecked much of the finest Thailand reefs on the Indian Ocean side.

John claps a hand on the taller man's shoulder. "Trust me: it'll be fun." _Even for a crabapple like you_.  
  
  


__________________

"This site is as good as all the magazines say," Dionisio opens their dive briefing. The Guatemalan Dive Instructor and tec diver has taken clients out there before and is visibly excited. "Not easy, especially at this hour with the tide patterns, but that means more plankton rising up. Much fish," he chuckles. "Also big fish."

All those who will be diving have gathered in the mid deck salon to the dive plan Dionisio and John had devised. It will take them counter-clockwise around each of the three pinnacles, although they may have to skip the last one if currents are particularly strong. Dionisio has found a sheltered shelf on the middle one which he says is perfect for spending a few minutes watching what might glide in from the open ocean. Turtles are likely to be spotted, as are large rays and sharks, barracudas and tuna.

John takes up a standing position next to Dionisio, hands clasped behind his back. "Maximum dive time will be fifty minutes, maximum depth thirty metres. We'll use the buddy system, do everything as we would on a dive centre outing. I want to see economical gas usage, solid finning technique, good communication and solid buoyancy, especially in a current."

He can trust that anyone handling cameras underwater will have perfected their buoyancy techniques so that they could get good stationary shots. He'd be checking everyone's ability to control ascent and descent and hovering in one's chosen spot. It's one of those things that shows just how good a diver is, irrespective of what their logbook might say. There's an art to inflating and deflating their vests, having just the right amount of weights in one's pockets or strapped to their belts. Finetuning and small changes in depth can be done just through breathing by experienced divers able to calculate their positions relative to the strength of a current; lungs filled with air will make a diver float upwards while a deep exhalation should make them sink if they are balanced just right.

John divides the group into three pairs, announcing Holmes as his own since they'll likely be doing the most demanding dives at the Entierros. Morten is to buddy up with Anderson, Dionisio with Joseph. That way, each less-experienced diver is paired with an instructor-level tec diver; John means to pick their brains diplomatically later to see if there were any issues of which he needs to be aware.

John had chatted with the Morten over lunch and found him a typical Scandinavian in his modesty. It turns out that the Swede had been recruited into the centre by Holmes himself after he'd learned of the young man's pioneering skills in magnetometry and side-scan sonar. Morten's father is a fisherman, and he'd spent much of his childhood on fishing vessels, keen to learn about navigation and sonar. This had led to a degree in engineering and then another in maritime archaeology; the Baltic is a splendid area for the discipline since shipworm does not thrive there and piddocks are much less a problem than in the Atlantic. Even old, wooden vessels can survive there. Morten had been a part of a team that had discovered an intact Renaissance-era shipwreck combining robotics with state-of-the-art wide-scan sonar. No wonder Morten has brought the most equipment: crate after crate of it have been piled up in the upper deck salon. He's been diving for over a decade and has done quite a lot of Trimix diving exploring deep Atlantic wrecks off the coast of Norway. He is a relatively quiet, no-nonsense guy with an obviously high work ethic. John hopes he'll appreciate the warmer clearer waters they get to enjoy here.

The group files out of the salon and heads for the dive deck. Every else is in swimwear and will don their wetsuits soon. Curiously, Holmes is already dressed in his own with a bathrobe on top. He'd stood at the back of the salon, arms crossed as the dive instructors went through the briefing, his posture signalling his annoyance at being forced into this dive. John had expected him to pipe up, to pose questions, to challenge their plan or even the reasoning for the entire dive, but instead, he had stood a silent, sombre vigil by the door. John has to admit he's irritated by the man's attitude. Nothing says that they can't all enjoy themselves on this trip, and as much as he battles the idea, Holmes' disapproval of his and everyone else's joy makes John feel a bit embarrassed about expressing it. _Doesn't exactly help that he humiliated me last night_.

At least underwater, John knows that he'll always end up being the proverbial one on top.  
  


_______________  
  
  


The sight of the ocean glistening in the bright sunlight from the dive deck dilutes John's irritation as always. His gear is ready, and he knows it'll take him just a moment to wiggle into his wetsuit, so he has a drink of water while watching the other organising their equipment.

Holmes walks out, and he's discarded his bathrobe. John relishes the chance to admire his physique in what must be a hellishly expensive, made-to-measure wetsuit. There are Kevlar reinforcements in areas that are subject to most wear and tear and ribbed spots in places that need a bit of ventilation. An understated pattern of red welts which look like an abstract approximation of jagged teeth runs down the front. The man has endlessly long runner's legs, a plump but firm arse begging to be grabbed. Just as John had deduced from seeing him with clothes on, he's beautifully sinewy and lithe like a dancer. John would kill to find out what he looks like underneath all that form-licking neoprene.

Having had his eyeful, John strips down to his black speedos and starts pulling on his wetsuit.

Holmes, having noticed finally that his diving partner had arrived, stops in his tracks and stares. "What is _that_?"

John glances behind him, but there's nothing there. "What is what?"

Sherlock points straight at his torso. "That... hideous thing."

Finally, a light blinks on in John’s brain. "This is my lucky wetsuit," he declares proudly. The wetsuit in question has served him well in many tight spots, and it doesn't matter that it's a bit worn and has holes; in these warm waters, he could dive in just his swimwear if he didn't prefer to have the protection of the neoprene from coral scratches. He does possess a newer thin wetsuit waiting in his cabin, but when he really needs to feel comfortable in new surroundings, it's got to be this old trusty Poseidon.

"Swedish quality never goes out of fashion," John jokes as he tugs on the sleeves to settle them comfortably on his arms.

"Right on," Morten comments from the other side of the deck.

"It's falling apart," Holmes protests exasperatedly.

"That's why it's lucky."

Holmes shakes his head. "Surely you don't want that monstrosity to be seen in a BBC documentary?"

He has a point, but John isn't going to give him the satisfaction. "Well, at least the holes aren't in any compromising spots. It'll be good for the viewers to see that not everyone can afford designer gear. Maybe they'll donate more funds."

"I would have thought that a dive professional of your calibre would purchase and maintain relatively new gear."

Holmes' disapproval is getting a bit funny, now. John decides not to disclose that he has brought not one but three wetsuits. "You don't know that many dive professionals, do you?" He asks rhetorically.

"I don't make a point of hanging around divers, no. For me, diving is a tool, not a sport or something I would do to waste time. Being escorted around with a bunch of tourists by a divemaster who harasses every marine creature found at sites frequented by a hundred divers a day is not my idea of recreation."

"Well, I find it fun even when it's work." _So, Holmes dives, but he doesn't enjoy it much?_ _Except when it's about his work?_ "You must have done quite a lot of recreational non-decompression diving before they allowed you on a tec course."

"I employed a British one-on-one instructor for two months, of which a sizable chunk was spent in Scapa Flow."

Sherlock is referring to a craggy diving area in Scotland where a huge bunch of WW2 warships have sunk, creating a wonderful but challenging, legendary site for wreck enthusiasts. Not a lot of day-trippers or holidaymakers dive there; it's a site for those serious in their interest in history.

"Fancy," John chuckles. "So, you did the bare minimum of everything so that you could get certified for tec?"

Holmes slips his tank into the strap of his BCD — the air-inflated vest that will allow him to regulate his buoyancy — and begins screwing the yoke attachment of the regulator set into the tank valve.

John follows suit with his own tank.

Holmes is adjusting his fin straps. "You're a freelancer, then? No steady contract with a dive school?" He asks, deflecting John's earlier question.

"I like the integrity being a freelancer gives me," he tells Sherlock. "I don't have to take shit from anyone, especially not some beginner with thirty dives under their belt who refuses to set up their gear in a safe manner. That happened once, and we started arguing. I told him he had fifteen seconds to set it up properly. He said that it's his gear and he knows how to use it. I told him that yes, the rest of the stuff is his, but the tank's from the dive centre. I took it off his BCD, ran it empty and told him to sit in the fucking car while we did the dive. He complained to the boss, of course. If the owner of the dive shop had told me off for it, I'd never have worked for him again. Instead, he gave me a pat on the back and told that twit of a customer to fucking get lost."

"Have you ever thought of starting your own diving centre?"

"Not many centres get very regular requests for tec courses, so maintaining the necessary infrastructure would be expensive. I'd hate to run the gamut of catering to beginner holiday divers for most of my paycheck; wouldn't want to have to do all the try dives and such."

"How do you find work? Do you advertise on LinkedIn, or…?"

John shakes his head as he straps his two dive computers—the second one for contingency—on his wrist. "I'd be swamped with offers if I did. No, I don't call them, they call me, and I prefer to have a mutual acquaintance who can vouch for new people if I have to dive with them. Government agencies and insurance companies are the exceptions since the insurance people don't usually need me to dive, and government officials are good customers since they always pay their bills. Except for Italy. Had to fight for the bloody Costa Concordia commission for months, and that was a tough gig."

Sherlock straightens his back and spits into the inside of his dive mask to form a fog-resistant film on the glass. "You dived the wreck for the investigation on why it sunk?"

"No, I was in a team that was tasked with locating three passengers who were still missing; they weren't among those rescued, but their bodies hadn't been found before the salvage workers were due to start their job in the wreck. My partner and I found two of the missing ones on the fourth deck; the third one was found a month later by another team on the third deck."

The look Sherlock gives him seems respectful, even impressed.

They continue assembling their kit without talking. The other divers are chatting excitedly; John can hear Greg quizzing Dionisio about what they might see so he knows what lenses and other camera gear he should instruct Anderson to include in his camera rig.

After lifting the tank onto his back and closing all the straps, John does a final survey of himself. Nothing is dragging out or dangling; in a current, he'll want to be as aero- or _aqua_ dynamic as possible. Tank valves are open, regulator and spare regulator are working, the air is flavourless, he's got his fins and mask and dive computer, straps have been fastened, his integrated weights can be easily pulled out of their pockets and ditched in an emergency, his BCD vest inflates and deflates, allowing him to regulate his hovering at different depths. Its dump valves are also working perfectly.

Beside him, Holmes is giving himself a pat-down as well as he checks that he's got everything. The gear they have on weighs like a backpack of bricks, but it's still much lighter than what they will be carrying on their tec dives.

"Buddy check," John announces gleefully. It's what the commercial diving organisations insist recreational divers should do before every dunk to make sure they know how to help their partner.

Sherlock has the audacity to give him an eye roll. "I'm all set. I have a mental checklist I go through meticulously."

"That may be, but you haven't established facts you need to know about me."

A patrician eyebrow is raised. "You have an integrated weight system operated simply by pulling hard enough forward that the Velcro rips out. No weight belt. Your fins are spring-loaded, and you carry spare rubber straps in your left lower pocket. Your signalling devices include a metal stick, a writing slate tucked into your right breast pocket and a whistle for the surface. You're wearing the Mares Hybrid Pro Tec Waistcoat model which has two dump valves; since I have memorised all the valve and strap locations of the twenty most common BCD models I doubt I need actually to _pull_ on yours to know where they are. I'm not interested in how much air you are starting this dive with; on non-decompression dives, I mostly carry a pony bottle to bail me out instead of chasing around for a _buddy's_ spare reg. You're meticulous and experienced enough to have solid routines in setting your gear up; it's doubtful there's anything sticking out or dragging which I'd not notice as I am looking at you right now.. Your computer's a Suunto D6I Novo with an old Vyper for contingency, both strapped to your left wrist. That's enough to be going on with, don't you think?"

"A buddy check is also a ritual that helps you get to know and be comfortable with a new diving partner," John argues.

"Having a stranger pawing at me has the opposite effect. Now, if we could hurry so we could be the first in the water; I'd prefer not to have to wait for the others to get in before us."

Holmes grabs his fins and heads towards the dive platform at the back.

"Aren't you forgetting something?" John asks dryly.

"I'm pretty sure I'm not," is the supercilious reply.

John grabs the dive computer Holmes has forgotten on the bench and hands it to him. "Mental checklist, eh?"

"You distracted me with your–– your–– inane rituals."

It's hard to be an arsehole underwater when you can't talk, but John is pretty sure by now that Holmes will be able to manage even that.

"Everyone set?" He asks, grabbing his fins after he receives affirmative answers from the whole group. He spits in his mask as well to create a fog-repelling film, quickly rinses it with a hose and arranges it onto his face. He lifts his neoprene boot-clad feet in the air one at a time, leaning on a pillar, and puts on his fins. His are open-heeled since they go on top of the boots. The combination, as opposed to closed-heel fins which require no boot, is a must on Malta where one often has to walk, all gear on, over sharp rocks to get to the entry spot of a shore-diving site. Doing it barefoot just wouldn't be possible, and there is often nowhere to shove flipflops. Having diving boots which double as shoes are the perfect solution, and they are also warmer and thus suitable for deep diving than a closed-heel fin.

The boat engine is on, and they are slowly going forward to combat the current. John takes up position beside Sherlock on the dive platform. There are no pillars at the edge to hold on to, so Greg and Terry, who have come down with two of Jose-Perry's junior crew members to assist and to film their first descent, offer their arms for the divers for balance and support.

"Can you radio up to tell Jose we're all set?" John asks one of the staff, and this is promptly done.

"Ready?" he then asks Holmes who nods and arranges his regulator into his mouth. John does the same and places his hand with his fingers splayed wide onto his mask and regulator to keep them in place. "Go!" he commands, and they leap in, head-first, crashing into the water.

They begin sinking fast since their BCDs had been emptied of air. Usually, divers jump in with their BCD inflated and take their time to assemble on the surface, adjust their masks and descend together, but when there is a current a fast, explosive entry such as this must be made.

Barely two metres below the surface, John begins to equalize his sinuses and his ears by swallowing, moving his jaws and occasionally gently blowing against the nostrils he closes by pinching his nose. A glance towards Holmes shows him doing the same. John hopes the man would glance in his direction so that they could exchange 'ok' signs but has to take Holmes' ignoring of him as a sign that he's just focussed. Usually, divers who get into trouble seek the attention of others unless they are beginners and in a complete panic, at which stage they usually quick-ascend and pop up like a cork.

Finally, Holmes looks at him, and John gets the hand signal he had been looking for. They're at a depth of eight metres, now, no longer being jostled by the waves. Not quite within visual range of the pinnacle down below, they are surrounded by an endless blue. It's far from quiet: sound carries well underwater, and John hears his own breathing and various distant echoes of life in the ocean. There's a clicking creak which he recognises as dolphins, a common sight in these waters. Visibility is about thirty metres; not as great as in the Red Sea, but still better than in many other famous dive sites. In some places, low visibility just means that plankton is so plentiful that it murks up the water.

John checks his gauges: _nothing to worry about_. Depth is now thirteen metres. A glance up shows the surface high above, the churning waves now only barely visible. The surface reflects light and looks almost like colourless oil sloshing in a massive container. Their bubbles are drifting up in swirling, dancing patterns.

A look down shows a shadow several metres deeper; the sight makes John fin a bit harder. The current is not too bad, allowing Holmes to stop finning and look up. OK signs are once again courteously exchanged; John is happy his new partner is at least adhering to standard diving etiquette underwater instead of being the stroppy loner he is above water. A few fin strokes more, and he's at Holmes' side. Holmes points a finger down, and John spots what he's trying to demonstrate: the looming shadows of the pinnacles. John sticks up three fingers, referring to the third pillar, then draws a semicircle with his other forefinger around them as a reminder of their plan. He takes the lead and brings them down to the first rock finger sticking out of the depths. Down here, behind the formation, the current dies down completely. They give their vests a puff of air to reach neutral buoyancy, then begin inspecting what is living on the coral-covered walls, not forgetting to survey the vast blue behind them.

Soon, they are joined by the four other divers. Greetings in the form of okay signs are exchanged, and each pair picks a route to meander around the pillars.

The site does not disappoint. Shoals of fish part as hunting trevally dart around, several colour variations of clownfish are guarding their chosen sea anemone homes fiercely. Snapper pairs are mating, giant, grumpy-looking groupers are lounging on the reef walls and moray, and garden eels are peaking out of holes. Brain corals, giant gorgonian fan corals and whip corals housing molluscs and bubble corals shining in an almost neon-bright green are all competing for John's attention. He finds the largest sea pens he has ever seen: feather-like cnidarian soft corals, they look as though a centipede's legs had sprouted tree corals. A feather star is swimming in free water — a rare sight — and it nearly attaches itself to John's knee before he gently brushes it off. _Not the best piece of real estate, little buddy_.

Besides watching the reef life, John watches his diving partner. He seems mildly interested in the reef but keeps checking his gauges more often than John would expect. After fifteen minutes, John asks him with hand signals how much air he's got left, and the answer he gets proves that Holmes' oxygen consumption is that of a very fit person's, and he's using the contents of his tank very economically. His buoyancy is exemplary, and he executes all use of his gear with routine; he doesn't even have to look at what he's doing with his hands to find things.

It's just that Holmes seems a bit… _jumpy is not really the word, but it does come to mind_ , John analyses. The man's movements as he takes out or puts away gear or adjusts something are fast and purposeful, but afterwards, he seems to take a moment just to hover and breathe. _It's as though he's…_ _relieved and almost surprised that everything's fine?_

A small octopus is living on the reef, using an empty shell half as a shield and a hat. It slips out a tentacle to lift the shell a bit so that it can look at John. He tries to be as still as he can so that he won't frighten the creature. It still seems to think he's an intruder since the shell is soon lowered, and a puff of debris launched at him from underneath.

He chuckles, then turns to check where Holmes is; he has stayed close to John and seems to be waiting for him so that they can move to the middle pillar.

The current on that side is much stronger, and John digs out a reef hook, prompting Holmes to do the same. A simple metal hook with a string, it allows a diver to anchor themselves into hard coral to prevent themselves from being slammed against anything or from being swept away by the current. Slowly, using the hooks as a sort of a vertical ladder, they make their way to the middle pillar and behind it where they are no longer at risk of being swept away. Holmes keeps up with his finning without trouble but seems hesitant to follow him. All in all, John gets a sense that he's just waiting for the whole thing to be over. _Why? This is a spectacular dive site; surely even he can appreciate that?_

Their depth is now twenty metres. Nitrogen narcosis shouldn't be an issue at this depth. _Besides, no one in their right mind will tec-train a diver who gets visibly narced at twenty_ , John reasons.

He stops to watch a dozen-or-so barracudas battling the current a few metres above them. _Pelican barracudas_ , he recognises. It's a special he's only seen in books. Ray-finned predatory fishes known for their ferocious nature and fearsome appearance, barracudas mostly act mellow on reefs. _They always seem to be just passing by_. Shoal members can number in the thousands, even blacken away the sunlight as they pass above.

Suddenly, someone tugs on his arm. It's Holmes, pointing towards the open blue. At first, John can't understand what he's riled up about, but then a shadow in the distance catches his eye. Then, another. Then, a few more. They're moving slowly in the same directions, and once they get a bit closer towards the range of visibility, John's visual memory instantly recognises the shape: _hammerheads!_ He has seen individual hammerhead sharks in Egypt and Hawaii; never a large group. Now, he can count no less than _eleven_ cephalofoil head shapes looming closer from the murky depths.

Eyes wide with excitement, he looks at Holmes, assuming that they'll, of course, stay put where they are to watch the spectacle.

Holmes has finned between two boulders on the side of the pinnacle. His eyes are fixed on the approaching sharks and from his bubbles, John can tell his respiratory rate has gone up a bit. Holmes quickly surveys his gauges once again, fingers fumbling to turn his dive computer the right way around his wrist.

John fins closer, uses his reef hook to tap on the man's tank to get his attention. Holmes' head whips around, and their gazes meet. What John finds as he studies his oddly coloured eyes is worry. Holmes gestures to him that they should circle back from where they came, and John shakes his head. He doesn't want to negotiate the current again; fighting it will shorten their dive since they breathe more out of their tanks when doing strenuous work.

Holmes stabs his fingers towards the open ocean. He's not quite hyperventilating but breathing faster than John would prefer. _It's just sharks,_ he thinks, puzzled. _Any diver would pay to see this._ In fact, he's missing most of the show nature is putting up by focusing on Holmes, but a buddy always comes first. He grabs hold of Holmes' shoulder strap and turns both of them so that they can watch the animals which are now making a swim-by of the pinnacles. _Look_ , John signals by trailing his middle and forefingers outwards from his eyes. _It's okay_ , he then signals, then points to both of them. _We're okay_. He flattens his palm and lifts it to his forehead to signal _shark_ , then gives Holmes a double okay sign which is usually used by divers to signify _how_ _fucking awesome is this!?_

With a delay, Holmes nods.

After the procession of hammerheads has glided past — John hopes Anderson had spotted them as well and snapped a few photos since he'd been carrying a compact underwater photo rig — John begins leading them towards the last pillar. Holmes seems hesitant, and John can't work out why until the man hits his own palm with his other fist to signal a strong current.

John checks his and his own air gauges; they're fine and can probably reach the fifty-minute mark. What is Holmes worried about?

Finally, his patience runs out. There's nothing wrong — at least nothing wrong that Holmes is willing to share with him — and he firmly signals that he should lead and Holmes follow and that they should head to the last pillar. With a shrug, Holmes does fin after him.

 _Did the sharks just spook him out?_ John wonders. Still, all in all, he is content with what he's seen. Apart from the forgetting-the-computer thing, Holmes has performed admirably in a strong current. If his tec skills and knowledge base are as good as his basic skills and his knowledge of ancient Greek rowboats, they should be fine. Anyone can have a bad dive, especially in a new environment. John wants to trust his instinct, and it's saying Holmes can certainly dive. But it may still take a few more outings before he's convinced Holmes' confidence matches his raw technical skill.

The rest of the dive provides some more exciting discoveries: turtles reside on the last pillar, and the strong current sweeping the top of it has created a haven for some rare soft coral varieties. John curses himself for not bring a camera; he rarely does so since looking after clients or other work he has to do underwater rarely gives him an opportunity to focus on just enjoying the views.

Their ascent is uneventful. Many divers get bored at safety stops — meaning a compulsory hover between three and six metres to make sure enough nitrogen has been removed from the body to prevent decompression sickness — but not John. He uses it as an opportunity to think back to what he's just seen and experienced, to have a quiet moment in the blue before having to pack up his gear and get social again. Once again, Holmes seems antsy, which breaks John's concentration a bit.

Once the boat finds them down current, they climb up the steps to the dive platform with their fin straps threaded onto their arms. Everyone but Holmes begins animatedly discussing the dive and comparing notes on species spotted.

"Need a hand?" John asks his diving partner when he spots Holmes struggling to get his hand out of the BCD strap as it's snagging on the dive computer on his wrist.

He doesn't protest, nor does he say anything welcoming, so John lifts the bottom of his tank to take the weight off his back. Holmes struggles free of the straps and John lowers the tank onto the deck.

"Good dive," John suggests. "Thank you."

"The corals were in excellent health," Holmes replies. "No bleaching."

"Yeah. I hope they conserve this site well. Wouldn't want it to turn into the Similans."

"I've not been there."

"Yeah, it's been established that you don't fun dive. Where did you do your beginner courses, by the way?"

"I did a referral course with the pool dives in Oxford and the open water dives in Cyprus."

"Did you do the Zenobia wreck?" It's one of the most famous wreck dives in the world — an RO-RO ferry which capsized and sank in 1979 close to Larnaca on its maiden voyage. It rests on its port side at 42 metres.

"What interest would I have in a wreck barely thirty years old?"

"My bad," John sighs and goes to put his gear away.  
  
  
  


**Notes for the Chapter:**

> [This is what it's like to encounter hammerheads on a dive.](https://www.youtube.com/watch?v=m41y9zOmHB4)
> 
> Yes, spitting in your mask works as a very good de-fogger. 
> 
> A pony bottle is a tiny air bottle one can use for a controlled emergency ascent during a dive if they are diving solo (rare, since most commercial dive training is based on the buddy system explained here) or simply prefer to have that contingency.
> 
> My primary dive computer is a Vyper, too. Good choice, John.
> 
> [Mola mola](https://www.youtube.com/watch?v=YBG0ZDWIPbg), aka sunfish, are strange-looking sea creatures which Nusa Penida in Bali is famous for. They are slow and curious and playful; regrettably, I have not met one in the wild yet. I have, however, met another gentle giant: [the Napoleon wrasse](https://www.youtube.com/watch?v=nZfjBJ2OrHY). 
> 
> The Nusa Penida area is also known for drift diving, meaning taking advantage of currents for a free ride along a reef — my absolute favourite diving activity! My wildest drifts so far have been in the vicinity of kandus (channels between atoll parts) in Ari Atoll in the Maldives. [Here is a drift dive in a very strong current](https://www.youtube.com/watch?v=9AdObY5AhZ0) — welcome to nature's own roller coaster! These divers stay calm, enjoy the fun, and then get close to the bottom and hold on to have a rest. The current is always milder close to a wall or the bottom.
> 
> Torres Des Dientes ("Tooth Towers") is fictional. Dive sites in the Galapagos Islands and the Chumphon Pinnacle in Thailand were used as inspiration for the site. [This chart of the Chumphon dive site](https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&ved=2ahUKEwjbm-3SqPfmAhXLtYsKHf5oAkQQjRx6BAgBEAQ&url=https%3A%2F%2Fwww.saireecottagediving.com%2Fchumphon-pinnacle-thailand%2F&psig=AOvVaw0co-pUSIKS9VEmizj14eHv&ust=1578686766808821) will give you an idea of what pinnacles are like.
> 
> [Here's info](https://www.youtube.com/watch?v=TGGyUwtfVtU) on how to spot signs of stress in a fellow diver. 
> 
> Feather stars are amazing creatures. [Here's one swimming in free water](https://www.youtube.com/watch?v=rRej1VKDgcE). A diving buddy of mine from Germany had one try to perch on his knee in Komodo, Indonesia a few days ago. 
> 
> Pelagic fishes live neither at the bottom or on reefs or coastal waters: they reside in the open ocean, also known as the pelagic zone. Other fish types are reef fishes and demersal fishes (bottom-dwellers). About 98 % of the total water volume on Earth is below 100 metres of depth. Deepwater corals exist but are a relative rarity: coral reefs need the sun to thrive, so they mostly grow at much shallower depths, which is, of course, convenient for divers. Less than 0,1 % of the world's ocean areas are coral reefs, yet they give a home to a quarter of marine species. They are under constant threat from pollution, dynamite fishing, crown-of-thorns epidemics, overfishing, excess nutrients and bleaching from water temperatures rising too much. I've personally seen the effects of bleaching in the Similan Islands. They have turned from being one of the most famous and colourful dive sites in the world into, at their worst, patches of underwater wasteland. 
> 
> [This video of divers encountering a humpback whale in French Polynesia](https://www.youtube.com/watch?v=vAZkzV41sCc) demonstrates well the soundscape of diving. Not a silent world by far!
> 
> __________________________
> 
> [Here's a map of the boat in this story to help with imagining where everything is.](https://66.media.tumblr.com/2d8792b96c353e7071209623c6eaf3f5/4e8c7e5e45adc7d2-5c/s1280x1920/db45161f77024b54e537d7eae1d5f035430c5151.jpg)


	4. A Smooth Sea Never Made A Skilful Mariner

The stars are out, and light from deck lamps is reflected on the waves the boat is making. When John finds Andrew on the top deck after dinner, his laptop is perched on his knees in an armchair. Its lid is closed, and the man is leaning his head back against the cushion. When he hears footsteps, he quickly straightens his back and flips the lid open, then exhales with relief when he notices it's John.

"Thought it was _him_."

"Professor Holmes runs a tight ship, then?

"Surprised?" Andrew smirks.

"Nope."

"He's not… he's not all… the way you've seen him is not all he is," Andrew painstakingly explains, his mind clearly whirring hard as he decides how much he should say.

"We all have work personas." Some more than others. John likes to think that he is mostly the way he acts when with clients or diving partners. Honesty and dropping masks and pretenses are important when putting one's life in a fellow diver's hands.

"He was different," Andrew insists. "Used to be different." He glances around to make sure his boss isn't within earshot. "A lot more fun."

For John, 'fun' and 'Holmes' seem like oil and water. All he's seen is a moody arsehole who seems to think fun should be repelled in case it ruins the science. John can't help being a bit amused by all the bristle, but it will eventually get old. And when that happens, it might just start getting on John's nerves. He's still curious about Holmes, though. He likes knowing what makes people tick, and he's certainly sensed that there are layers in the man. _Depths perhaps very few have explored. Few would dare to try._

"I thought things would get better when the Centre finally solved its funding problems; we have a big new donor and all. Maybe Sherlock's just sick of doing the fundraising, having to justify our financial needs to all the higher-ups."

"You call him Sherlock?"

"Yeah. Morten does, too, but not when there are others around the professor doesn't know. He'll correct us then to use his proper title."

_Very concerned about how people see him, and hiding behind titles and that fancy suit?_

"Is funding why he finally agreed to this documentary?"

Andrew frowns. "No, there's a charitable Foundation that's stepped in to finance our projects, not the BBC. I was surprised when he told us there was going to be a documentary — we all were. The BBC's been trying to get the Centre involved for years, but it's the last thing I thought he'd ever say yes to, especially now that we don't really need the BBC money, do we?"

"How was he more fun? What's changed?"

Andrew shrugs and drums the keyboard with his fingertips without really pressing down any keys . "He was less tense. Not quiet at all; more of a show-off, really, and could speak a million words a minute about our projects regardless of whether the other person was listening or not. Good speaker at conferences but you wouldn't want to put him in a panel; he'd eviscerate the other participants."

John laughs. "I can imagine."

"No, you really can't. I know at least one guy who was the hottest rival for his current post; they were put together in a conservation panel three years ago when the application process was going on. It seemed that the way Sherlock humiliated him on stage led to him withdrawing his application. At the Centre, when I first started working on my PhD under him, you'd be hard-pressed to find a more passionate, more excited, more dedicated researcher. He pushed himself through all the diving training in what must've been record time so that he could see all the sites for himself."

"He tells me he went to Cyprus, then Scapa Flow."

Andrew shrugs. "I don't know the details. I know it was abroad; he took some time off for it and got the Centre's Board of Directors to agree that he'd be reimbursed for the expenses."

 _The Centre has money, now,_ John reminds himself. _It appears that Holmes very reluctantly agreed to this documentary deal even though he no longer needed the funding. Why?_

__________________

After having a word with the captain on the command bridge after dinner, John is heading down for his own cabin. Just as he's about to turn a corner on the upper deck, his ears pick up Holmes' voice so he slows his steps.

"I told you, I won't discuss any of that. No. Again, no. If only you'd respect my––"

John's hand brushes against a pair of swimming trunks clothes-pinned to the side railing, and the wet garment makes a splat as it hits the deck just as John takes the corner and comes in view of Holmes' back.

The man flinches, pivots on his heel and as he takes in who's intruding on his obviously tense phone call, a curious mix of emotions shifts on his features. The apprehension flirting with anger which his conversation had brought on turns to surprise, then embarrassment.

"Sorry, I'll just––"

"We're going out of range," Holmes snaps into the phone and presses the end call button.

It's a satellite phone so it's _never_ out of range. Holmes shifts it behind his back to hold it in both hands — as though he'd been doing something forbidden.

"Who was that, then?" John asks, sipping his beer. _No harm in asking._

Sherlock looks positively scandalised at his curiosity. "None of your concern."

John points, beer in hand, somewhere behind Sherlock to indicate the phone. "Someone called you earlier when we were leaving dock. That the same person?"

"Have I not made myself clear?"

Something makes John press on. Holmes is a mystery, John likes mysteries — especially in such handsome packages — and solving it is the best entertainment available on the boat. "No need to bite my head off. It just sounds like you're… those calls aren't making you happy, that's for sure."

"Why are you––" Sherlock starts asking, then resolutely snaps his mouth shut. "You're about to lecture me on distractions as a diving hazard as an excuse for being nosy, aren't you?"

 _Bloody genius telepath_. "I guess you saved me the trouble. And I'm hardly _nosy_."

"So, you weren't interrogating my assistant earlier about our funding?"

"It was just a conversation." _Sheesh,_ John thinks. _Everything's classified information with this guy_.

"If there is something you want to know, you can ask me instead of going behind my back, pressuring my staff."

"I'm not pressuring anybody, _Sherlock_."

The use of his first name gets a raised brow from Holmes. "I wasn't aware we were on first-name terms, _John_."

"We'll be diving partners, and I am sure as hell not calling you Professor Holmes down there."

Holmes studies his expression for some time and doesn't seem to be finding the answers he's looking for there. "Very well. We'll all be stuck in this vessel together for some time." He rocks back on his heels, stiffly clasping his wrist behind his back. "If that's all, then––"

"I do have a question," John hastens to say. He wants to keep Holmes — Sherlock — talking, now that they're, strangely enough, not arguing.

"Yes?"

"Where––" _come up with something and make it fast; keep him talking!_ "––are you from?"

"I'm not sure how that's relevant to––"

"It's not relevant, okay?" John steps closer, aware that he's beginning to sound exasperated. "It's not relevant but I'm _interested_ , alright? I like people, so sue me." _Give me a chance to like you_. "I like to know their stories. The diving community has some fantastic characters, I'm sure the same applies to academia."

"I think you'd find most in the archaeological community quite dull."

_All the more reason to get to know you. You're not dull, are you… Sherlock?_

Hesitantly, Sherlock hovers in front of the open-air lounging area in the aft of the deck. There are some books there and some papers prevented from blowing away in the breeze by a few scattered diving weight belt parts.

John puts his sweating beer on the table, and Sherlock shifts the papers away from it.

"I was born in London, but my father was a naval officer. We moved to Portsmouth when I was an infant."

"Did you like it there?" John is from the coast himself, from Canvey Island overlooking where the Thames joins the sea. He'd hated the place with a passion; the proximity to water had been the only virtue of it.

"No, but it did introduce me to marine archaeology. Have you visited the Mary Rose museum?"

"Yeah, the old one. I heard they've done a spectacular job with the new version."

"Indeed. I was seven years old when they lifted the ship up from where it had been half-buried in the silt. My father took me to see it rise from the sea after she sank in the Solent in 1545."

"That was at war with the French?"

"The ship served Henry VIII in several wars including those against Brittany, Scotland and France. You're correct; it sunk leading an offensive against an attacking French fleet."

John wants to ask about Sherlock's family but decides against it. He's skittish as is to talk about himself. "Where did you go to school?"

There's a grimace. "A Catholic College in Southsea called St John's. I was a boarder though our home was close; my father's duties took up so much of his time. I also suspect it was because he thought I spent too much time loitering at the dockyards. The workers there let me be, let me do my own things. Learned all the slang."

_No mother, then?_

John nearly chuckles at the idea of a small Sherlock speaking like a seaman or a boat carpenter. "You knew your lammies and ticklers and crab fat and poultice wallopers, then?"

"You did the same in your youth?"

"My father was a shipbuilder. But he drank away his job and his family." _Best offer a bit of honesty myself, encourage him to do the same?_

After his father became unemployed and died in a traffic accident, John's mother who was a nurse took him and his sister to London so she could find a better-paying job. John never found himself getting very attached to the city; the Thames was not the same as the North Sea his dad had taken him to on the test runs of the new ships before they were delivered to the buyers. _Had to make sure they were sea-worthy and manoeuvred well_.

"Oh." Holmes doesn't quite know what to do with that statement.

John gets the distinct impression that he'd rather be doing anything other than this conversation. _Personal social exchanges make him uncomfortable?_

But, it appears that Sherlock's curiosity gets the better of him. "University?"

"Leeds. Medical school."

"I'm aware of where — from your CV. I wanted to know why you don't practice?"

"I did do one year of bits and bobs, then the lure of the navy got me. I mostly do just dive medicals, now."

Something dismissive flashes in Sherlock's gaze. "You should certainly visit the new Mary Rose building. They managed to work out how to replace water in the cellular structure of the wood with polyethylene glycol."

"So, they don't have to constantly spray it with something anymore?"

"No. They open viewing area is tightly climate-controlled. Joseph worked on the project, took samples of all the wood areas before the PEG spray to study the microbiome. He's hoping for us to find some wooden structures at the Entierros, hopefully from an era close to the Rose so that he could compare notes on those."

John glances at the papers arranged on the table. "What are you working on?"

"Something Morten was supposed to do, but he's not been very thorough. He has a good knowledge base of civilian vessel wrecks, but he's still working on his war history."

Holmes pulls out a sheet of paper. "The Museum of Science and Industry in Chicago houses a rarity — a WW2 German submarine captured during the wolfpack mission. They are redoing the ammunitions part of their exhibition and have asked for a consult."

"Wouldn't they have someone in their staff who could do that?"

"It pays quite well and there's… there's a mutual acquaintance who got us the job. Such things bring a bit of extra funding and good practice for my PhD students so I welcome that extra work. If only Morten hadn't done such a hack job of it. He has talent and logical thinking but his tolerance for hard academic archive research needs work."

Sherlock opens his laptop screen and shows John a photographed sign: _'T5 acoustic torpedo detected the sound of propellers from enemy ships and moved toward them. The acoustic technology was quite complicated and quite sensitive.'_

"Is that incorrect?"

"It's a gross oversimplification. This is their current sign. If someone is interested enough in the torpedo that they bother to read the information provided, why not provide some actual technical information instead of childish blanket statements ' _being complicated and sensitive_ ' — what sort of stupidity is that?"

"There's got to be a compromise between understandable and detailed, I guess. After all, kids at the museum read these signs, too."

"That compromise should not be to infantilise your entire audience. I am going to suggest that they create animations explaining the acoustics recognition system."

"Yeah, that could work."

"The torpedo contained so-called hydrophones. Once launched, it travelled in a straight line for about four hundred metres, after which the hydrophones attempted to identify the loudest ambient noise. The problem was that the technology wasn't there yet to provide the system with a library of sounds they should _not_ react to; a submarine firing a T5 had to dive in order to avoid being hit with the bloody thing themselves since they were invariably the loudest thing in the proximity. Hence the 400-metre margin."

"What triggered the torpedo to explode?"

Sherlock's eyes glimmer with excitement momentarily. Then, it blinks out as fast as it had appeared, and he clears his throat to appear more collected. "Most who are unfamiliar with torpedo technology will assume they detonate on impact. However, the T5's pistols — that's what their fuses are called — came in two types: impact and _magnetic_ , and the latter would detonate upon encountering the magnetic field created by a ship."

"That's amazing."

"Quite, yes. Whatever one may think about German politics in the first half of the twentieth century, their war technology was ingenious. American supply vessels were terribly helpless against the wolfpack until they learned to find the submarines before they struck."

From films and popular nonfiction science books he's read about the world wars, John knows that the wolfpack strategy was so successful that the US armed forces imitated the tactic with their coordinated attack groups. The battle of who got to rule the Atlantic had left many interesting wrecks at the bottom of the ocean.

Sherlock seems to have now finished his explanation of this side project; his hands are resting in his lap, and he's picking at a cuticle, eyes downcast. He mutters, "Don't let me keep you from more important business. I am sure there are others on board who can entertain you."

John can't decide if Sherlock is expecting him to jovially dismiss that statement, or if the man just wants to get back to his museum sign -rewriting. "Okay, but before I forget: I need your gas consumption data for my blending calculations," John tells him. He's been meaning to ask for it but hadn't got around to doing so because prior to this conversation, every single one he's tried to have with Holmes so far has ended up with the man trying to bite his head off.

"I shall deliver that to you right now." Sherlock digs out a memory stick, copy-pastes a few Excel spreadsheets onto it and gives it to John. "I'll expect that USB stick back since it has my backup copies of some photographic material related to Andrew's thesis.

"Yeah, sure. I'll get this back to you in the morning." He'd half expected Holmes to put up a fight, to insist John had no business asking for such info. He's pleasantly surprised how well he'd chosen the moment to ask for what he needed. "Thanks."

"You need them to do your job," Sherlock acknowledges. "And it appears I need the fruits of your labour to do mine."

___________________

  
  
On his way to his cabin to retire for the night, John is still racking his brain over Holmes — _Sherlock_ , he reminds himself — as much as he tries to shift his thoughts to what he'll need to do tomorrow to set up all the gear and to start making gas calculations. He'll need lots of data about the wrecks that have been chosen for diving and sea seamount topography. That will mean talking to Sherlock some more. _Looking forward to it._ It's as though the man changes completely from a human porcupine to a quite endearing ball of enthusiasm in a beautiful package when he gets to talk about what he's interested in.

 _Still doesn't bode well for this trip, putting someone like Holmes in charge of leading the team_. The man is not the first academic John has met whose personnel management skills are lacklustre, but he might just be the worst yet. Is it fear he rules his team with? Andrew seemed to think he'd withdrawn from actually leading anybody lately. Clearly, Holmes expects people to just manage on their own and to perform perfectly without input from him. _Maybe it'll be better in just a two-man team, once we get some more experience of diving together_. Nothing had gone _wrong_ at Torres, but John can't say he'd enjoyed being Sherlock's partner on the dive.

 _Prove me wrong about you_.

  
________________  
  


The next morning, one of the dinette tables has been taken over by Holmes and Morten.

"Om du har användat en software filter for att få de här hydrotopografiska kartorna att stämma med apertyr-ekolodbildena måste du presentera den algoritmen som programmet är baserat på," Holmes explains fluently.

"Då måste jag kontakta tillverkaren. Kan vara att den faller under affärshemlighet," Morten replies, sounding a bit disappointed.

"Vi löser det om det behövs. _Jag_ löser det om det behövs," Holmes declares, and pushes away Morten's laptop to get to his plate of eggs.

He notices John approaching the table and forks up the last bits of them quickly before dabbing his mouth. "Morning, John."

"Morning. You speak Swedish?"

"He speaks a lot of things," Morten says politely.

"Quite elementary for someone who is familiar with English vocabulary and grammar. Norn was much more a challenge," Sherlock replies disinterestedly.

"Norn…?" John's brows hitch up in confusion.

"Morten?" Holmes asks with a raised half-brow and pushes his chair back to leave.

"It's an extinct North Germanic language that was spoken in Orkney and Shetland."

"And Caithness," Holmes adds.

"Doesn't explain why you speak it."

"Plenty of historical wrecks in those areas."

"Right. So, how many languages do you––"

"Twenty-three." With that, Holmes concludes his input in the conversation and climbs up the stairs.

Morten points a finger at his own head. "Fotografisk–– um, he's got photographic memory. He can learn a dictionary in a few days. Add grammar and well, there you go. New language learned."

"But why Swedish? I assume that was the modern version."

"My _pappa_ doesn't speak anything else. He was demanding two years ago that I come home for the summer season to help with the catch — to do the navigation and all while he handles the nets. I've always done that. Holmes insisted he needed me for a project, so he learned Swedish and called my dad."

"That was nice of him."

Morten leans back in his chair, strokes his beard. "He didn't speak very nicely. He didn't do it for me; he needed my gear which I've built myself. It was a good summer, though. I signed up to do a PhD under him then."

"So, he's good at languages. What about diving? You're more experienced than him. Have you tec dived with him?"

"Yeah. About ten times."

"Is he alright? Does he… panic?"

Morten seems surprised. "No. Never. Everyone gets worried sometimes, you know, but he controls it. You can see how hard he works at that. He's good."

"What do you mean, 'how hard he works at it'?"

Morten shrugs. "I don't know how to better explain it."

"So, he does panic, but controls it?" John presses.

"Is it panic, if it's contained?"

"You may have a point."

"He says every maritime archaeologist should dive. To see things intact where they have ended up. Otherwise you lose information. Even with video and photo, he says it's not the same. He can… he does things with silt behaviour patterns and current charts and working out how a ship has ended in the spot and position the wreck is in, and the way things grow on wrecks… I've never seen anyone do anything like that. He _reads_ the wrecks. It's like he can reconstruct back what happened in his head as he looks at the artefacts. He can imagine what has been looted and what has decayed away."

"Amazing."

"Yeah, pretty much. When he's working, he has this total focus. Might ignore the dive partner, that's for sure, when he sort of forgets about anything else than the wreck. I've had to remind him to check his gauges sometimes. He gets a bit carried away."

Suddenly, they can hear animated voices and footsteps from the deck above. John goes to the small sofa area in the aft of the dinette to look up. Greg and Andrew are one deck above, leaning over the safety railing on the side and hooting as they point towards where the boat is heading.

"Look!" Greg hollers down at John. "We're here!"

There are more birds making occasional reconnaissance circles around the boat, now — a sign that there is land in the proximity. In the distance in front of them, the cone shape of a volcano draped in green rises from behind black, jagged cliffs. Two other islands flank the shape in the front like gates.

John's heart skips a beat. _The Entierros.  
  
  
  
_

**Notes for the Chapter:**

> [The Mary Rose Museum](https://maryrose.org) is exactly as spectacular as Sherlock describes. I spent a lovely day exploring the Portsmouth docks area with 7PercentSolution last year, and it also served as excellent research for this fic. There are very few museums like that in the world, and having visited both, I have to say that as a museum, the new Mary Rose complex is better, more fun and more informative than the Vasa Museum in Stockholm, though the Vasa is much more intact. The St John's Catholic school is a real institution in Portsmouth. I think we can all get a chuckle out of imagining Sherlock having to attend such a religiously influenced school…
> 
> The information in this chapter about the T5 torpedoes of the [U-505 German submarine housed in the Chicago Museum of Science and Industry](https://www.msichicago.org/explore/whats-here/exhibits/u-505-submarine/) comes directly from photos I took on my recent Chicago trip. It's a fantastic exhibition and features one of the only still functioning Enigma machines.
> 
> Sherlock and Morten are discussing a research article Morten is writing; Sherlock is telling him that if he's using a filtering algorithm, he needs to explain the maths in the article. The problem is that Morten will have to request that data from the company who has manufactured the equipment he's used, and such stuff often falls under trade secrets. Sherlock promises him that if such an issue arises, they'll solve it — or he'll solve it. Sherlock and Morten aren't the only ones who speak Swedish around here. I'm a bit rusty, though, so mistakes may be present.
> 
> Lammy = short, single-breasted Fearnought coat made at the dockyards, crab fat = navy grey paint, tickler = hand-rolled cigarette, poultice walloper = First aid man.
> 
> Let's also have a word about sharks since AO3 told me my author's note for chapter three couldn't fit all this in. 
> 
> Thanks to Jaws and other horror films, these beautiful apex predators have gained an undeservedly bloodthirsty reputation among humans. In reality, shark attacks against divers, in particular, are very rare outside the feeding grounds of certain particularly aggressive species. Swimmers and surfers move in ways that mimic seals and other prey; divers are so different that sharks are mostly just confusedly curious about us. Even a chance encounter with a Great White or a Tiger shark on a dive would most likely leave you alive. [Tourist shark attacks seem to correlate with chumming](https://www.theguardian.com/world/2010/dec/07/what-made-sharks-attack) — pouring fish bits into the sea to attract sharks for viewing, and such practices should be discouraged. I have had the honour of meeting blacktip reef sharks, whitetip reef sharks, nurse sharks and close relatives of Great whites, Grey reef sharks. Those encounters rank among my greatest diving experiences. Many shark species are endangered and in need of our help — they are no more a monster than any other predator in nature. They deserve our admiration and respect; the sight of a Grey reef shark changing its course and doing a patrol round to check you out is a shot of adrenaline like no other. [Watch from 4:10 onwards as a group of freedivers enjoying the company of tiger sharks](https://www.youtube.com/watch?v=Zy3kdMFvxUU). I hope my next shark encounter to happen in July when I head to the Azores; I hope to meet [these guys](https://www.youtube.com/watch?v=BInpTsM6Bu0) in particular. 
> 
> The only sea creatures that have ever attacked me are clownfish (yes, those cute little Nemos who guard sea anemones; one rammed my mask because he felt that I got too close to his crib) and [these bloody arseholes](https://www.youtube.com/watch?v=mLgtlTz-fDY) with teeth big and sharp enough to snap through coral.


	5. Outer Space on Earth

**Notes for the Chapter:**

> We're getting close to the parts of the story which will warrant a trigger warning. [That warning is here](https://jbaillier.tumblr.com/post/190273060460/trigger-warnings-for-thermocline), to prevent me from having to spoil a lot of story content in the tags. Beware that the link contains MASSIVE SPOILERS. If clicking the link doesn't work, copypaste https://jbaillier.tumblr.com/post/190273060460/trigger-warnings-for-thermocline into your browser. Some Android phones seem to have an issue with Tumblr links.

The next five hours on the boat are busy ones with little time to relish their new scenery. The captain and Dionisio take the RIB out to survey the currents. The lagoon they are moored in looks calm, now, but when northern winds blown in the area, they will create devastating currents through the straights leading to the spot. That is likely the reason so many unsuspecting ships had been wrecked here, and the area dubbed the _Graveyard_ by the Guatemalan navy. The wrecks which the armed forces frogmen had spotted here are smaller and older than the larger warships assumed wrecked on the ocean side of this circle of islands — and the ones here at the bottom of the lagoon might well be historically significant.

"Nobody is sure who has come through here and when the islands were first discovered," explains Greg.

He is doing a bit of narrating in front of Anderson's camera while standing on the dive platform while John changes the battery to his spare dive computer. He has started his always meticulous bookkeeping, and established a basic stock of pressured air, oxygen and Trimix bottles, all clearly marked and separated from an area where he'll store empty tanks.

There's a lot going on on the other decks, too. Charger cables are cluttering up every horizontal surface on the boat: besides phones and satellite phones and laptops, there is Anderson's camera gear which has taken over the upper deck salon since the space is dry and clean and has the biggest table, and several other diving team members have their own, smaller underwater cameras. John had once bought a GoPro just for laughs but hasn't used it much. He certainly hadn't brought it along for this trip.

Sherlock, Morten and Andrew have set up a complicated rig of sonar and who-knows-what-else in the sofa area just aft of the dinette. Before mooring, they had instructed the captain to take them concentric circles around the lagoon, discussing animatedly whatever data those boxes were picking up. Morten had tried to explain to John the intricacies of his high-resolution acoustic sensors which, combined with an underwater hyperspectral imager, could reconstruct 3D models of the ocean floor with very good sensitivity to recognise what was just silt and muck and vegetation at the bottom, and what was wood or metal.

"A bit like a heat camera underwater, but better," the Swede had grinned.

John will have to take his word for it. Though he had no trouble understanding the basis of imaging systems during medical school radiology courses, the wave physics of what Morten does go way beyond his comprehension.

"Oh, it's rather simple, really," Sherlock had mused after spotting John's confused expression. "The shape-from-shading technique is a classical approach in computer graphics, so since the data gleaned from underwater objects is presented and processed on PC screens, we can use the known technological math to create the reconstruction without having to invent the wheel by translating the data with a complicated algorithm to something that computer would understand. Creating a reflectance map is based on the simple context of reflected light depending only on a radiance related to the cosine the camera — or sonar — angle, and we of course know that angle. We're using the Ikeuchi & Horn approach of starting with an initial guess of a surface shape — sonar shadows compared against an automated database of wreck shapes created by Morten. Then, we refine to minimise energy function and use a series of recordings of the same spot to eliminate the effect of current and to create a photometric stereo which will then give us reference points for 3D."

"I still don't understand."

Sherlock had sighed, regarding John with profound disappointment. "Perhaps you should have that printed on a T-shirt. Some people just don't have the capacity to understand how eloquent silt is."

The images Morten had then shown John from the two articles he'd published with Sherlock did look amazing, even if the colour scheme of bright fuchsia and neon light blue in the reconstructions was a bit psychedelic.

John had understood at least that the work the Oxford team is doing today will help them choose an area of the Graveyard to explore underwater tomorrow. They won't need their tec gear since the deepest parts of it lie in less than thirty metres; John has, however, prepared double tanks of Nitrox to give them more time at the bottom. The extra oxygen displaces the nitrogen their bodies are absorbing at depth, making decompression sickness less of a risk. Also known as the Bends and DCS, it's caused by dissolved nitrogen bubbling in tissues and blocking blood vessels if a diver ascends too quickly instead of being off-gassed safely.

"Keep me company for a beer?" Greg asks, having finished his filming.

Even though his part is now starting proper, he seems to be the most relaxed of the bunch. When the others had bustled about, he had donned a sunhat and sunglasses and enjoyed an extended siesta on the top deck with a pile of water bottles and a bottle of sunscreen by the chair. "Never too early to start on my South American tan," he had told John.

"Nah, I was actually discussing a potential night dive with Anderson."

"Yeah?" Greg asks his cameraman. "Reckon there'd be anything down there we'd want to film?"

"Not taking the full rig down," Anderson says. "It's been a long enough day."

  
______________

  
  
After dinner, John is sitting on the middle aft deck gluing a neoprene patch into his wetsuit hood when Sherlock slams open the door of his cabin which is the closest one to the seating area. He rounds a corner towards the cabin John knows belongs to Greg and pounds his fists on the door.

John leans to the right in his sofa seat so he can see the narrow side corridor. The pounding metal music that has been sounding from the direction of the cabin Sherlock is trying to charge into doesn't stop — instead, the door opening makes it much louder.

"You will cease this racket _right this instant_! No one is getting any work done with this barbaric noise going on!" Holmes announces.

"Nobody else has complained and John over there's getting his work done just perfectly," Greg says, leaning on the doorway and regarding Holmes with a nonplussed look. "In fact, I think he heard him humming along earlier."

Sherlock gives John a glare as though he's done something criminal before sizing up Greg again. "I'm the leader of the expedition and I say what goes and what most certainly _does not_ ," he announces snootily. "We're neighbours, so I expect at least some level of common courtesy."

"Like the politeness you're oozing right now?"

"Acquire headphones or throw that recording overboard, I don't care."

"Or what?" Greg smirks. "Can't exactly pop down to a shop to get a pair, and I need my music for artistic inspiration."

John shakes his head and grins. Clearly the man's new status as a talking head for BBC nature productions is getting into his head — or he's developed a taste for riling up their mordant professor.

"I'll fire you."

"You didn't hire me; the BBC did, and there's no getting a replacement out here."

Holmes huffs.

They seem to end up in a staring contest until Greg gives a crooked smile. "I'll turn it down."

"You'll turn it _off_."

"Not until…" Greg glances at an imaginary watch, "eleven in the evening."

"You're clearly making this a matter of principle, that principle being to annoy me as much as possible." Sherlock's tone has gone up in pitch, making him sound irritably and snidely superior.

 _God, he's even crankier than usual_ , John thinks.

"I could say the same, Sir Expedition Leader. Have a great night," Greg concludes as he closes the door. The volume of the music is turned down but only a notch.

Sherlock has been left standing behind the closed door, his entire form bristling. He runs his hand through his hair which the humid salty air has turned into a curly cloud of frizzle. "Unacceptable," he mutters just loud enough for John to hear.

John expects him to go back to his own cabin, and he does pivot on his heel but, instead of taking a step forward he leans his head down, grabbing the safety railing as though having a sudden bout of dizziness. John's thighs tense as he prepares to launch out of his seat to help, but Sherlock recovers quickly and starts walking towards the back of the boat. As he makes his way past the seating area — looking as though he hadn't even noticed someone is there — John can see his face better. It's a worrying sight. He's pale, sweaty as though nauseous, there are dark shadows under his red-rimmed eyes, and he looks completely exhausted. He stops to rub his temples with the heels of his palms, pinching his eyes closed.

"You alright?" John asks, and the man flinches, finally noticing he's not alone.

"Yes, quite."

"Quite but not entirely? Didn't see you at dinner."

Holmes manages to summon up some righteous indignation. "That's not what I meant." He squints towards the sunset and manages to look amusingly cross-eyed for a moment.

John drags himself up from the sofa and walks up to him. "You don't look like you've had much sleep."

"Jet lag," Holmes dismisses with a flick of his wrist.

"Flying in this direction?" John never gets it flying west from Europe.

"It's always worse for me this way. Recovery is not made any easier when that racket is going on next door."

John purses his lips. "Right."

"Besides, I don't need sleep when I'm working."

"Like hell you don't."

"Admittedly, diving makes me more tired in the evenings than usual, and yesterday was certainly an ordeal."

"Me and Anderson were thinking of heading out for a night dive in the lagoon later. Dionisio snorkelled out a bit further to scout out the currents and the conditions should be fine. I was going to ask all the divers if someone else might want to come, but you look like you could use a rest instead of a dunk."

"You don't get to decide when I dive or don't dive."

John regards him sardonically. "You're not diving looking like that."

"There's _nothing wrong with me_ ," Sherlock announces sternly. He rubs his arms with his hands, which John notices are shaking a little. He looks… distracted. Distraught, even. It doesn't surprise John that he then heads towards the door to his cabin.

"Wait." John's tone is bordering on an order, and Holmes does stop. "I meant what I said. Being too tired is plenty enough reason not to dive. You know it."

"Sometimes, when on a boat expedition, it's easier underwater; less––" Holmes pinches his eyes shut as though he has a headache, "–– _clutter_. None of that godawful music, no vibration from the boat, no engine noise. People are easier to tune out." He opens his eyes, blinking, looking past John towards the horizon. "I can _feel_ everyone on this boat, boxing me in without any chance of respite." To John he sounds, for lack of a better word, a bit claustrophobic. _Paranoid, even_.

Holmes then seems to catch himself; his mouth falls open as though astonished at what he's just admitted. Embarrassment makes an appearance until it is quickly and neatly wiped out, replaced with a steely look that's diluted by the fact that John can see his composure threatening to crumble.

Greg's cabin door opens and he strides out, battered old satellite phone in hand. "Holmes?"

"What _now?!_ "

"Call for you. Bloke said you haven't been answering yours, but I have no idea why they'd be trying through me." He extends his hand, fingers wrapped around the phone.

Sherlock snatches it and wastes no time in pressing the disconnect button. It takes him a few tries; John notices his fingers fumbling a bit. "If he calls again, hang up. Better yet, don't even answer." He heads for his cabin, shoving the phone at Greg as he walks past the man.

Greg rolls his eyes. "Alright, whatever."

 _He didn't even check who the person on the phone was_ , John realises.

_________________

The ocean is like a moonlit mirror as John and Anderson walk to the edge of the dive platform. The heat is still sweltering, and the 7mm wetsuits they'd chosen for the night dive are making them sweaty after mere minutes of wearing them, but John finds comfort in the thought that he soon gets to drop into the cool water. It's astounding how much sunlight contributes to how warm one stays on a dive.

They go through a gear check, making sure weight belts are attached right and easily accessible and effortless to open and dump, ensure that tank valves are open and that the main and spare regulators working. Unlike Sherlock, Anderson stages no protest over going through this routine. Just the two of them and Dionisio, already bobbing on the surface rubbing spit into the inside of his mask, were game for a night jaunt into the blue.

Their plan is to explore the underwater life on the sloping reef which begins from the shallows on the lagoon side of Isla St Joseph de Betancour, surveying the animals that come out only in the dark.

Lanterns in the dive deck and an underwater floodlight are turned on by the captain to guide the divers back to the boat. The gear they're using the lightweight, standard scuba gear they had used at the pinnacles with the addition of two diving lights each. Night dives are best done at familiar, shallow sites and in little to no current.

John does a backward barrel roll with the air bladder of his BCD inflated so that he won't start sinking. The sound of hitting the water is like an amplified version of the din from putting one's ear in a big clamshell. Bubbles whirl around him and a brief glimpse down before he bobs up to the surface shows just darkness. A few kicks bring him back to the surface, where he arches his arm into a giant OK sign for the staff and Anderson, who's waiting on the diving platform.

One additional figure suddenly appears behind the safely railing on the dive deck just as Anderson hurls himself into the waves: Holmes. His hair is sticking up wildly on one side as though he'd stuck his fingers in an electric socket, and the opposite side is a bit flat as though he'd slept on it. He looks half-asleep still as he dips his heads towards first his right shoulder, then the left as though getting rid of cricks. He raises a hand to John who nods, not wanting to wave a hand in return lest the staff think he's signalling distress. To John's relief, Holmes doesn't appear to be donning any dive gear. He yawns instead, looking like someone has just shoved him out of bed.

_Has he taken a nap? Why would he come down to watch us go?_

John is convinced he has a pretty good first instinct when it comes to assessing what people might be like as diving partners, but Sherlock confuses him. He is obvious meticulous, conscientious and very, very organised, but John is deeply troubled by what had appeared to be an obvious lack of self-awareness about his physical state. Diving when exhausted, distracted or ill can kill a diver — and their partner — because it makes them sloppy and unobservant. It appears that the man has raced through technical diver training, seeing it just as a means to an end. Back in the old days, before fast-track commercial training schemes, people had to earn their spurs before they would ever pluck up the courage to approach an expert to see if they might train them for tec. Now, anyone with a thick enough wallet for the courses and the gear can do it. A certificate is not equivalent to experience.

Maybe John is ready to admit he'd made the decision to join this expedition quite lightly. Then again, that's how his decision-making works: he knows he can handle nearly anything the underwater world throws at him, and he just couldn't resist the chance to dive somewhere tourists have not ventured yet. His assumption had been that he'd be working with professionals whose credentials and experience he wouldn't have to doubt — after all, this is a BBC thing and they tend to go for the best. Yet, he can't shake the feeling that he needs to keep a close eye on Holmes to make sure the man isn't diving beyond his skills. For that reason alone, John remains convinced that he was right to insist that he be the one to pair with Holmes. His graduate assistants wouldn’t dare to tell their supervisor off, even when it might make all the difference between life and death.

 _Focus_ , John tells himself. _Don't waste this dive on worrying about bloody Holmes._

Holding his breath since he hasn't put his regulator back in his mouth after jumping in, he presses his mask into the water to look down, pointing his light into the depths. Now, he can see a black sandy bottom with clusters of hard corals. Water is distorting the perspective and distance, making it look closer than it is. Dionisio had done a measurement; the water is about twelve metres deep here, close to where the bottom reef fringes upwards towards the island.

Anderson has jumped in and is now cleaning his mask.

"Ready?" Dionisio asks when the cameraman has replaced the mask on his features.

John readjusts his mask strap and holds his regulator close to his lips. "Yeah."

They shift positions so that they're facing each other, grab their inflator hoses and pull them upwards so that they can use the buttons to empty the bladders and descend. John glances towards the boat once more just as he begins to sink; Holmes has disappeared.

 _Stay in the moment_ , John reminds himself. _Don't waste what most people never get to see._

They sink slowly, feet-first, watching one another and exchanging OK signs — thumb and forefinger tips joined with other fingers fanned upwards. As expected from an underwater photographer who does not have the luxury of a sturdy ground for image stability, Anderson's buoyancy control skills appear to be exemplary. John soon decides to ditch a bit of weight off his belt for the next dive; since the Mediterranean is so salty and thus buoyant, he still tends to slightly overestimate his weight needs for other seas even at this skill level.

Hovering near the bottom, careful not to brush against anything, they adjust the air in their BCDs to neutral buoyancy and begin exploring. They try not to point their lamps straight at the denizens of the deep—who the hell would want to wake up to a giant lamp pointed right into their eyes?

Coral colours are at their best when lit by the LEDs, and many strange species have crept out of their daytime hiding places to feed and mate. A pair of goat fishes are sleeping side by side on a rocky home they have constructed. Coral polyps have opened in the thousands to sift the moving water for nutrients. There are crackles and snaps as though from a cereal bowl if one listens carefully: crustaceans using their claws and fishes and other reef inhabitants cracking bits off coral to do a bit of housekeeping and construction. There are no less than four parrotfish mucus bubbles attached to a coral boulder; the bubbles are like protective blankets designed to ward off predators while the parrotfishes rest. John has seen the remains of those bubble nests often on early morning dives, floating by in free water like giant boogers.

Anderson appears to be in micro photography heaven as he snaps countless shots of tiny, colourful reef life such as nudibranchs, also known as sea slugs, many of which look like jewels or glass sculptures.

There's a series of boulders which look as though a lava tube has collapsed. One of them looks like the maw of some ancient sea monster in the inky dark blue. Thousands upon thousands of damselfishes are seeking shelter in that rock maze, their eyes glistening in the cones of dive lights. The three divers spend ten minutes examining the rock walls for octopuses and lobsters, occasionally glancing behind them into the endless, velvety underwater night. The thought of the vastness of the ocean always gives John a pleasant shiver, especially when diving on walls at night when the blackness spreads itself both underneath and behind him.

On their way back towards the boat, they stop finning and simply hover, turning their lamplights against their chests. Then, they wave their arms in front of them, and the plentiful plankton in the water begins to emit fluorescent light. It's like thousands of tiny stars twirling across their visual field. John has seen this hundreds of times when night diving, but the sight never gets old. The last time he'd seen it was in a narrow bay on Gozo called Mgarr Ix Ini which had been recently re-opened after Angelina Jolie and Brad Pitt's movie stopped shooting in the nearby cliffs. The cafe in the bay had doubled its prices and added a pizza called Brangelina to their selection. _Yet another reason to get out of Malta and find fresh water to explore._

Once they've had enough of playing with the plankton, John glances at Anderson and Dionisio who have turned their backs towards the bottom and are floating motionless in mid-water, watching the moonlit surface far above. Content that his buddies aren't about to disappear off somewhere, John turns onto his back, too, gazing up at the distant, cold light and his bubbles floating up towards it.

It's strange how tons and tons of water separating him from his usual, humanly habitable environment don't feel like a crushing pressure at all. He never feels more free, happier, or more in tune with the universe as he does down here. He has wondered if there is something wrong with him because he needs to sink himself down to the bottom of an ocean to banish the restless hum in his bones that has plagued him all his life. He has never wanted anything permanent in his life, never a steady job, never a steady relationship. The only constant in his life is the ocean, and when he's in it, it's all he needs.

Admittedly he sometimes wonders if it would be nice not to wonder whose face is on the pillow next to his in the morning — or to have a guarantee that he won't wake up alone. _I like waking up alone, though. I like organising my life the way I want, enjoy not having to compromise and negotiate with anyone._ Who the hell would put up with his lifestyle?

He closes his eyes for a moment, hovers weightlessly like an astronaut of the deep.

Finally, Anderson seeks his attention to clanging his tank with his metal stick. John flops onto the usual diving position of belly down and checks his air. _Plenty left._

But, his companions don't seem to be interested in doing a gauge check. Instead, Dionisio is pointing his own reef stick towards where they've come from and John starts to make out five ghostly shapes in the distance. When they get a bit closer, he realises they are five mobulas. Also known as eagle rays, they are huge, beautiful, spotted creatures which look as though they are flying.

John gives Anderson a double okay to signal he's sharing that wonderful sight. Anderson signals a suggestion of staying down for another fifteen minutes to which John and Dionisio agree; any longer, and he would probably get uncomfortable cold after not finning much in the past ten minutes.

 _It's funny,_ John thinks, and this thought is not new: _it's funny how I feel that I belong here, even though no human was ever supposed to survive in the deep.  
  
  
_

**Notes for the Chapter:**

> A macro lens is what you use to take pictures of things very close by. The sexy science talk early on in the chapter in mostly nonsense with some real related vocabulary thrown in.
> 
> Night diving may sound scary and complicated, but it really isn't. In fact, even beginners tend to use a lot less air at night; the darkness somehow makes people relax. While you can see lots of fish sleeping on the reef in the dark, there's also lots of life that creeps out to feed and mate at night. Night dives are often timed so that there's still daylight when you go down, but it's not strictly necessary. Here's [a very demonstrative video](https://www.siladen.com/video-night-diving-bunaken-national-park/) of the nightlife on a reef from Bunaken Marine Park in Sulawesi, Indonesia, where I have night dived once. 
> 
> [Want to see some mobulas?](https://www.youtube.com/watch?v=ChXDVHO8JEQ)
> 
> What I have explained here about bioluminescent plankton is real, and it is so.effing.amazing. I have experienced it several times when night diving at Mgarr Ix Ini on Malta. There are sepia (cuttlefish) there, which are one of my absolute fave sea creatures. 
> 
> Perhaps my most memorable night dive yet happened in the Maldives: we stood on a sandy bottom of a lagoon, stuck our dive lights upwards and watched giant manta rays eating plankton attracted by the light. Here's [a video filmed by a member of our liveaboard group](https://vimeo.com/190461242?utm_source=email&utm_medium=vimeo-cliptranscode-201504&utm_campaign=29220&fbclid=IwAR2a3mhqnf9KyVuP-PcQeN3Erx_2r2CNRzxrH8flebZT7WAaOJ0pSw5LYKQ); the night dive starts at 04:35 but the rest is great, too. Yup, one of those divelights is mine. The mantas swooped down so close you could feel them gliding past. At one point it looked like a Swedish guy in our group was wearing one as a hat.
> 
> Sea slugs might seem like a weird thing to be enthusiastic about, but many divers — especially photographers — are, and once you see pictures of them it's easy to understand why. [Just look at them!](http://www.oceanwideimages.com/categories.asp?cID=65) and [here's some more](http://www.divegallery.com/morebran.htm) and [some more](http://www.seafocus.com/gallery_nudibranchs.html).


	6. In The Arms of The Ocean

Carrying his tank from the storage area to his spot on a bench, John spots Joseph and Morten adjusting the straps of a brand new -looking whole-face masks with a radio unit on the side.

"Fancy. Centre's got pretty generous funding these days, then? Or are those courtesy of the BBC?" He asks.

"They were donated to the centre for this trip by the Hilti Foundation chairman," Joseph says.

John has no idea what the Hilti Foundation is. "Got a pair of those for the prof and me too?"

"Yes, but professor Holmes won't use them," Morten replies. "He said so."

John slides his tank into a round hole cut into the wooden bench that keeps it from rolling around when the boat rocks. He rolls his neck; he's been lifting and carrying the heavy cylinders all morning to prepare for their first Graveyard dive. _Thankfully, it's only going to be double nitrox tanks for today and not proper tec stuff_. "Why on Earth not?"

In commercial diving, radio systems and whole-face masks have become an industry standard, but in scuba and recreational tec, they're still a rarity. The last time John had worn them was on his Costa Concordia recovery gig.

"Now how did it go…" Joseph takes a moment to try to remember, "he said… he has to 'filter out enough witless babble above the water'. He says he is fine with hand signals and his… _ardoise_?"

"Writing slate?" John suggests, and Joseph nods, looking relieved. "Well, it's his loss. Which channel have you chosen?"

"Three," Morten says and rises from his seat to pull out one of the masks from a crate for John. "We can give the professor's mask to Dionisio."

"Good idea," John confirms.

"Holmes speaks BSL, by the way," Morten says. "That's one of those twenty-three languages. Kind of useful underwater."

John chuckles. "Well, it _would_ be, if anybody else spoke it."  
  


_______________

  
  


An hour later, the diving team has barely assembled near the bottom of the Graveyard when a cold influx of water sweeps through their group.

 _Must be a sudden push from the straits,_ John reasons while grimacing at the sudden chill. _I hope the weather isn't changing._ He glances towards where he'd last seen Dionisio, considering asking him through the radio whether their local expert thinks this cold flow would be cause for concern in terms of the currents he has said seem rather unpredictable in the lagoon. Inflows of water of different temperatures are hardly uncommon on dives; the ocean water is not a homogenous, perfectly blended mass but consists of layers and zones of varying salinity and temperature.

John's head swivels around a bit when Dionisio can't be found where he'd assumed. Finally, John spots the dive instructor behind Anderson and Morten, heading towards Sherlock who had been the last one down despite John's attempts at coaxing him to descend together. _Yet another breach of standard buddy rules_.

John can't really see what's going on until he circles the rest of the group. The source of a strange movement he'd spotted somewhere behind Anderson turns out to be Sherlock. Instead of hovering neutrally above the sandy bottom like the others, he is attempting to keep himself stationary by kicking with one leg while trying to grab onto the other. John sees Dionisio getting close, then reaching out for Sherlock's calf. He's clearly made the same deduction that seems rather obvious to John from what Sherlock is doing: it's bound to be a cramp caused by the influx of cold water. Usually, such nuisances happen later during a dive when their body heat has been drained by the water. But, if a diver is dehydrated and their electrolyte balance is out of whack, it could happen at any time.

John is about to alert Dionisio to the fact that Sherlock probably hasn't noticed his approach, but it's too late — the Guatemalan grabs the man's calf. Cramp or not, Sherlock is startled by this so violently that the leg swiftly launches an instinctive, vicious kick at Dionisio's groin. The dive instructor doubles over, face strained in pain, but he manages not to sink down to the bottom since he'd fine-tuned his buoyancy before attempting to assist the other diver.

Sherlock finally stops writhing long enough to puff a bit of air into his BCD to keep from crashing down onto the bottom coral. He then continues to attempt grabbing his fin. What he's doing is precisely what divers have been taught in order to stop a cramp, but his fins are long model and his legs even longer, and any diver who's ever suffered from this problem knows how much easier it is to fix it with the support of a diving partner.

John pressed the button on the side of his mask to activate the radio. "Let me try," he tells the rest of the group and makes his way to Sherlock.

When the man notices him, he freezes on the spot, his whole form tense as if expecting another assault. John stops finning, wafts downwards with his palms which is a standard divers' signal that means _calm down_. Then, he shows two slow, reassuring OK signals both as further assurance and a question.

Sherlock is breathing hard — perhaps from pain, perhaps from anxiety — but at least he's paying attention to John, who is now signalling him to slow down his breathing. It doesn't seem to do the trick, so John points at himself, then Sherlock's calf. He touches his fist to his own ankle to ask sure he has the right diagnosis — the signal means _cramp_.

The wait for a response from Sherlock is agonisingly long, but finally, he gives John a hesitant nod. His entire form seems to be telegraphing _stay back_ , but John isn't about to leave him in trouble.

He makes his way to within an arm's reach of Sherlock, then lifts his legs into a position where he appears to be sitting cross-legged in mid-water like a levitating yogi. Sherlock is so tall that he needs to position them in a way that compensates for it. He pats his own bicep and beckons Sherlock closer.

Sherlock — pale and nearly hyperventilating, now — reaches out to curl his fingers around John's arm and holds on for dear life. John then pats his knee to signal that the man should use him as a chair. After hesitation is broken by another bout of pain obvious in Sherlock's expression and a sudden attempt to grab his calf once again, he complies and slides his bottom onto John's knees.

One arm around his partner's waist, John reaches out for Sherlock's calf with his other and begins kneading it. Even without a shared radio channel, John can hear the pained groan this elicits when he attacks the hardened gastrocnemius muscle. Finally, the tissue yields, becomes pliant. John finishes his ministrations with the stretch Sherlock had been attempting: he leans forward and grabbing the tip of a fin and holding on to it while Sherlock slowly straightens his knee and lets out a long inhalation. His breathing has begun to settle already, perhaps because control over fixing the situation had shifted to John. He's still very tense; John can feel the tremors in his shoulders against his arms.

He shows Sherlock the OK sign again and receives the same in response. Sherlock extricates from his arms and gains a few metres of distance between them — not too far that they'd be too separated from one another, but clearly, he wants to regain his personal space.

The whole episode has lasted not two minutes yet had felt much longer to John. It's never good, starting a dive with any kind of a kerfuffle.

Sherlock is now at the edge of the group, facing the direction they are supposed to be heading and impatiently beckoning the rest to follow him. 

Sherlock had not deliberately made their descent take so long, but it's a bit arrogant to be now getting antsy. Were they both wearing a radio set he might verbally rib the man a bit in a good-natured manner. Since Sherlock's back is turned, all John can do is to starts a brisk fin kick to follow his partner.

_____________

Dionisio is the designated compass reader, and John the backup. A hundred metres towards where the PhD student and Sherlock had located something in the reconstructed sonar data which had made them rather riled up on the boat, the seagrasses give way to another stretch of sandy bottom. At first, John thinks they're seeing just driftwood and rocks at the bottom, but suddenly Sherlock shoots out an arm to stop the group, then beckons Morten and Anderson to start recording the area.

Sherlock digs out a note-taking slate and a graphite pencil. He begins jotting down notes, not all the words of which John, hovering above him and reading over his shoulder, recognises. Morten takes photographs while Anderson operates the film camera; he'd told John that a part of Oxford's deal with the BBC was that the science team would receive copies of all the raw film material for research use.

Once a thorough survey has been made of the approximately twenty-by-twenty-metre square area, Sherlock pulls on a pair of diving gloves and begins wafting above patches of sand to use the movement of the water to reveal what lies beneath. In the next thirty minutes, the Oxford team reveal the distinct shape of a wooden boat keel and what John is sure might be the metal attachment of a rudder. It's not a large ship, but big enough to be carrying what a round of wafting by hand at the edges of itsshape yields— a cannon buried in the sand.

Sherlock digs out his smaller writing slate and jots down the word COG, and shows the slate to John.

HOW CAN YOU TELL? John writes below the word when Sherlock offers him the pencil. He's read enough about maritime history that he knows a cog is a ship type — one with a sail.

His answer is an eye roll, and Sherlock then fins to give Morten some instructions. John decides to join Joseph, who is poking around some pieces of ceramics which had been close to the thickest wood beam remains. He's taking samples from the silt surrounding the sand-buried ceramics.

John tries to imagine what this small ship — probably one with sails since he's pretty sure there are faint outlines of a mast formed from scattered fragments and metal bits — had looked like on the high seas, the crew tending to the sails and eating whatever had been in this pots or amphoras or whatever they are called. _How old is this thing?_ He wonders. It doesn't look like much to the untrained eye, but John is enough of a maritime archaeology enthusiast to know that sometimes, the simplest discoveries can be the most significant ones.

_I'm sure Sherlock will explain to me all about this thing once we get back to the boat._  
  


_____________  
  


John's prediction turns out to be accurate.

Sherlock has barely ripped his mask off back on the dive deck before he starts animatedly discussing their discovery with Andrew, who's been eagerly awaiting their return back to the surface.

Once he's packed his gear away, John joins the science team in the dinette and plants himself on the same bench with Sherlock to listen to their enthusiastic conversation about the day's findings.

"A cog, then?" he asks Sherlock when there's finally a lull in the conversation. When excited, the professor speaks a thousand words a minute, and his eyes are sparkling with excitement.

"Before the cogs and the caravels, Europeans were limited to coastal traffic in balingers and barges. No discovery of a cog has ever been found this far from Europe! John, have you any idea how much this will change about what we know about the timing of the beginning of the age of discovery?! It's always been assumed that cogs were not seaworthy enough to cross the Atlantic let alone to extend sea travel all the way out here since they would have had to sail around Cape Horn and then up the length of South America. Cogs were the larger load- and war machine -carrying ship of the 1300s, but still smallish — typically with less than thirty crewmen and a hull length of about twenty metres. What on earth were they doing out here? There had to be a convoy; there is no way just one boat would have attempted a sea journey of this proportion. The Graveyard needs to be fully surveyed; we need to establish a research _base_ here, not just stage a couple of expeditions!"

Joseph clears his throat. "Cogs were clinker-built, and they would have used the best oak for any vessel sent on a long journey; my samples should be able to show where the wood originated from. Likely from the Baltic; they were quite common in the Hanseatic trade period — think thirteenth and fourteenth century. Likely from the Prussia area."

"Wasn't Prussia founded in 1525?" Anderson asks.

Sherlock gives him a dirty look. "Not the _kingdom_ of Prussia but the _region_ of Prussia. According to legend, the name comes from the chief priest and brother of king Widewuto who lived in the sixth century. The earliest record of a region then called Brus comes from the eighth-century anonymous cartographer who wrote the _Descriptio civitatum et regionum ad septentrionalem plagam Danubii_. Now stop lowering the IQ of the entire deck by interrupting," he commands Anderson, who snorts.

"What ships did they use during the later, um… proper age of the discovery, then?" John asks, aware that he probably sounds like an even worse idiot than Anderson in Sherlock's books.

Joseph opens his mouth to respond, but Sherlock cuts in, and strangely enough, he doesn't look the least bit disappointed by the question. "In the 1400s and 1500s two important ship types were developed: the _caravels_ for exploration and _carracks_ for warfare and heavier commerce. Caravels went first, and when a route was established, carracks would follow."

John has seen pictures of caravels. He knows they are broad-beamed vessels with two- or three-pole masts. "That's what Columbus used, didn't he? Caravels?"

"Yes, he did," Sherlock confirms. "Most schoolchildren will be able to name his three flagships so no need to attempt to impress me with those," Sherlock informs him. "What is often forgot about is the _redonda_ , a more advanced version of the caravel; instead of a main lateen sail requiring lots of crew, it had a square sail which offered speed when running offshore. Morten?" he asked, and the Swede perked up, "Average speeds for caravels?"

"Four knots, top speed eight knots."

"Elementary knowledge, but satisfactory answer," Sherlock declares. He then leans down on his haunches to rummage for one of the maps in his large canvas bag reserved for them.

The salon door opens, and Greg walks into the dinette. "Hey John, heard Holmes gave you that lap dance you've been pining for."

Sherlock stands up, stretching into his full height just behind John, who expects him to say something scathing but instead, there's an awkward silence before Sherlock grabs his bag and all but jogs upstairs.

"Aaaaand thanks for wrecking any rapport I may have managed to achieve with that guy," John snarks at a now slightly red-in-the-face Lestrade.

He goes to pour himself some fresh orange juice from a pitcher left on the table. _It's not as if they don't all know what happened at the bar on the first night. They were all there._ Still, it seems a bit uncouth to pick on someone just because they'd said no. On the other hand, Greg had meant to tease John, but that didn't change the fact that the subject of the joke was someone who'd supposedly been coaxed by John into something they didn't––

_Why am I being so fucking sensitive about this? It's just normal bloke talk. If prim princess up there can't handle it, he shouldn't… what?_

What had Sherlock Holmes done wrong, and what should he have done differently? _Nothing_ , John admits. And clearly, that jab of Greg's had hit home hard enough that it had rendered Sherlock speechless. After the rocky start, John has felt as though he needs to walk on eggshells with the professor, even though — on a surface level — he seems perfectly capable of putting everyone in their place. Is it because John's pride had been more badly wounded by the scathing rejection than he wants to admit, so he needs to believe there's more to it than just Holmes finding him unimpressive and unattractive? Or, is it the same sixth sense that has served John pretty damned well all his diving career so far?

  
_________________

Mariza comes to collect their juice glasses; John had just finished his third glass sitting in the dinette watching some of the footage Anderson had shot. "It's like living with teenage boys here," she complains in a good-natured manner. "Laundry everywhere, dishes all over. Your mothers have a lot to answer for," she laughs.

After Sherlock had left the deck for his cabin with his maps and laptop, not a peep has been heard until he strides back into the dinette, ignores everyone and flings something into the sea with a splash from the back before marching back to his cabin.

John frowns. "What on earth was that?"

"I think it was his… satellite phone?" Andrew says, alarmed. "We have more of them, don't we?"

"The captain has one, and I've got one," Greg says. "Still a waste of bloody money."

"Is he… all there?" Anderson points at his own head. "I mean, we've all _thought_ of the question, I'm sure."

"Is anyone?" John asks angrily and unfolds from the bench. _I need to talk to him. I don't even know why, but since something's bothering me, something has to be bothering him._

The clock is ticking: their first tec dive is mere days away. He makes his way to Sherlock's cabin door.

A knock produces no response at first, so John tries a second time.

"I'm working; go away."

To John, he sounds less angry than he would have assumed. Resigned, perhaps; uncertain, even.

"It's me, Sherlock."

"Why would that make any difference? Told you. _Working_."

John cannot decide whether he should take this as a sign that the shadow of Greg's jibe has befallen him, too, or if this is just Holmes being Holmes.

"Working with a side order of phone-tossing. I need a word."

"I don't have time for your nonsense, John."

John pinches the bridge of his nose and exhales. He's surprised when Mariza appears with a plate of fruit and knocks on the same door. "Professor Holmes?"

"Right, yes, hold on." Sherlock's tone instantly changes to something approaching amicable.

He cracks the door open just enough that Mariza can pass him the plate. John notices his hands shaking a little. Before Sherlock can pull the door closed again, he jams an arm in between.

"What are you still doing here?"

"Told you, I need a word."

"I need to eat."

That's the oddest excuse John has heard yet from a man who very rarely joins them at mealtimes. " So now you're having lunch and _not_ working."

"I can multitask." Sherlock's tone is now icy, his patience obviously drained.

"I didn't know we had room service."

"Mariza has been kind enough to accommodate me. Thank you, that'll be all," he tells the woman hovering behind John.

"Just eat, and we'll talk at the same time," John insists.

Sherlock glares at him. "You're not setting foot in here."

"Alright, _fine_. Eat, and we'll meet in the lounging area on the upper deck after."

"Sunbeds on the top deck."

 _Why do you always have to call the shots?_ "Alright. I'm sorry for what Greg––"

The door slams in John's face.

  
_______________  
  


  
"I have an inquiry," Sherlock declares when he appears at John's chairside fifteen minutes later. John takes off his shades and steals a covert glance at the man's hands: rock steady. _It's not just my presence that makes him uneasy or anxious, then_.

Sherlock folds himself into the next chair, bare feet tucked to the side of his bottom. He's changed his clothes and is now wearing a white linen dress shirt and navy shorts. All onboard are barefoot; the decks are clean and shoes rolling about would just fall into the sea or make people trip and fall.

"You have an _inquiry_ ," John repeats. Why such a formal word; what's wrong with just asking a question? And _wasn't I supposed to be the one with those?_

"Why have you appointed yourself some kind of a busybody when it comes to me? Don't think I haven't overheard you asking questions about me, seen the way you watch me like a hawk."

John gapes. "What?"

"I need a diving partner, not a general manager, nutritionist, doctor or some kind of–– of––"

"Friend?" John suggests.

Sherlock blinks, then seems to decide he hasn't heard right or doesn't even comprehend the word. "I don't need you to attempt to engage with me. I need you to do your job."

"That's exactly what I'm doing when I'm trying to make sure you're fit and healthy and not stressed out and your gear's working right."

"Our philosophies seem to differ in what the duties of a diving partner entail."

"You know the BBC hired me to do more than that."

"The BBC is not here. I am, and I'm in charge. Consequently, your job description falls under my jurisdiction."

"Why are you working so damned hard to repel everyone? No, I am certainly not your fucking nursemaid or babysitter, Sherlock, but if I don't start seeing evidence of responsible decision-making and self-care, I won't dive with you."

"Then you'll force me to do our tec dives solo."

"Nope." John crosses his arms. "You forget who's the gas blender around here. No trimix, no tec. Good luck with that."

"You're holding our helium hostage?"

Their gazes are locked in a battle of wills, which Sherlock ends up losing. _He actually looks… impressed?_ John marvels.

"What do you want, John? You're expecting and demanding all these abstract things."

"I don't trust you, not yet. And I can't dive with anyone I can't trust. Well, I trust you, but I can't _trust_ you, if you get my drift."

"I really do not."

"I've seen that you have all the technical skills which have been needed so far. Clearly, you have all the tec theory down pat if you know it as well as you know your academic field. But safe diving is about more than that. Looked in the mirror lately?"

"I routinely look in the mirror. What of it?"

"You look like a wreck. Are you eating enough?"

"I'm positive I eat more regularly than anyone else on this boat."

"How about sleeping a full night?"

"I don't sleep well when I'm working."

"That's precisely it. If you don't sleep, you'll get sloppy, concentrating is hard, DCS risk is increased. Tired people make mistakes."

"I'm not 'people'."

"No, but you're a diver, and when they're tired divers make mistakes; they get themselves or their partner killed. Whether you're eating or not since nobody sees you do that is debatable, but you're rail-thin, look anaemic like a bloody vampire, your hands shake and then not shake, and your mood's all over the place. When did you last give yourself a break? A proper break, not just a loo stop with a banana before burying yourself under all those sonar readouts and maps again?"

"I can't afford to––"

John grabs his skinny wrist as he stands up and starts pulling Sherlock towards the stairs down.

"What––" Sherlock starts to protest, but John quiets him with a look before letting go of his hand and nodding towards the upper deck. Holmes follows him there and then along a side corridor to the front of the boat. As they pass Mariza on the stairs, John asks her to follow them with four bottles of the sports drink the salon fridge is stocked with. They pass the command bridge, the kitchen and a laundry room until they arrive at the very front of the boat on a tiny sundeck that can barely fit one deck chair and an air mattress. It's completely shaded by a triangle of sail fabric pulled taut with ropes attached to the sides of the boat. John had found it on their first day when he'd been exploring the boat after they'd come on board; the captain had assured him it was for everyone to use.

Far from the engines, high up enough so that the sound of waves hitting the sides isn't very loud and far enough from the heavy metal soundtrack of Greg's cabin, it's the quietest nook on the entire boat.

"I'll take the chair; you grab the mattress."

"To what end?"

"I'm sure you can work it out."

"I have too much to do to waste time lounging around."

"Doctor's orders."

"You're not my doctor."

"I'm _everybody's_ doctor in here, not just yours." John crosses his arms. "I'll get off your case when you stop _being_ one."

Looking as though the pillow might bite him in the arse if he isn't careful, Sherlock lies down on the mattress and John plonks himself down in the chair.

"Why are you sitting there?"

"To make sure nobody disturbs you. Unless you want me to go? I won't, by the way, not until I hear some healthy snoring from you." John has seen this before; divers who get too riled up by impending work and being stuck on a boat with people they don't know to get any sleep. John can feel some of that same restlessness, but he has learned to deal with it through experience.

When Mariza appears, carrying four bottles of Lucozade on a tray, Sherlock is fast asleep.

____________________

The next morning, at breakfast, Holmes no longer looks like a pale spectre. He'd napped for three hours under John's watchful eye; John had read a novel in the pleasant shade of the small sundeck. They'd finished off all four bottles of the electrolyte drinks, then returned to their cabins. John hopes his partner had used the night for sleeping, too. They will continue exploring the cog wreck in the lagoon today and hopefully move on to larger wrecks in a day or two when the Oxford team have got enough of the Graveyard. They won't be able to excavate any site on this trip fully; doing such things underwater requires more time and equipment than they have brought with them, but what they can do is make a solid initial survey and record enough data to convince financiers that the Entierros is a project worth funding long-term.

Sherlock goes to sit alone in a smaller table in the dinette. They had all been asked for their egg preferences the night before, and for the next days, instructed to jot down what they want on a list on the wall. John has enjoyed such a luxury before on liveaboards he has worked on, and since this is what the boat is usually used for, he isn't surprised.

John takes a seat on the stairs next to Holmes' table. The man gives him a passing glance, then continues reading what look to be copies of army reports. Sherlock's breakfast consists of two hard-boiled eggs, one of which has been sliced neatly up to cover a piece of buttered toast. In contrast, John's plate is laden with sliced tropical fruit, pancakes, fried eggs with the yolks still deliciously soggy, a blueberry muffin and a pile of bacon.

Holmes has three cups of black coffee in front of him, one already half-drunk.

"Your bladder's going to explode," John points out, cocking his head at the coffee. Having lots of it before diving is not a good idea; dehydration has been associated with a heightened risk of decompression sickness and coffee and tea are diuretic. At least Holmes has a water bottle in front of him as well.

"My bladder is my business."

The dismissal doesn't surprise John, but it lacks the old bite. Perhaps they've reached an uneasy truce? _I'm allowed to fuss, and Sherlock might occasionally comply just to get me off his back? I can accept that._

"What's that you're reading?" John asks, refusing to acknowledge the fact that Holmes obviously does not want company. He wants to gauge the mood of his diving partner; even just not feeling up to it emotionally is plenty enough reason to cancel or abort a dive. Stress and panic are the biggest killers for divers, not sharks or running out of gas.

John wants to get to know him. There are lots of things he's seen that he likes in terms of diving: Holmes is obviously fit, a meticulous planner, detail-oriented and, for a relatively inexperienced tech diver, at least he is gone through lots of formal training. But, John has seen other things he likes, too. Interesting things. Passionate things. It's just that they seem to be hidden under some shroud of… what?

He still hopes he might convince Sherlock to wear the radio system. It sounds as though he won't be keen on much communication at all, preferring to focus inward on his own tasks. What if John needs his help, or Holmes has a problem he doesn't recognise as one? Will he be paying enough attention to a partner, and would he reach out if something is troubling him? Is he one of those divers whose vanity and pride would never allow them to tell their partners they have a bad feeling or a bad dive if it means the dive should be called to an end?

"It's one of the reports the Guatemalan navy has kindly declassified for us, detailing a survey of a wreck field as part of their combat diver training. Not many of even the bigger wrecks have been reliably identified, and the sight that awaits us on the ocean side of the bigger islands should be visually enticing enough for the documentary crew."

He gives John one of the photocopies. It's a drawing of a large area of the seabed around the southern half of the Isla Santa Maria Madre, with four wrecks and plenty of debris drawn on it. The suspected identities of vessels have been jotted down on the sides. "Are these your theories of what these are, then?"

"An educated guess." Sherlock points at two of the names. "We know two fishing boats wrecked somewhere close to that island; a storm in 1912 prevented them from returning to the shore and wrecked their navigation systems. The army wasn't using these islands yet, so they were uninhabited. The boats likely made it to the archipelago but could not call for help and eventually sank. The fishermen perished on Isla Santa Madre, leaving behind enough documents that we know what happened but not precisely where in the shallows. The boats are small and likely devoid of any interesting artefacts, the shapes and artefacts reported by the navy frogmen in that area south of the island are a good fit for them."

One of the names Sherlock has jotted down looks like that of an American warship: the USS Courage. "What's this?"

"The Mexican and the Guatemalan navies used to buy lots of decommissioned vessels from the US Navy. That was an Avenger-class minesweeper-destroyer which sank due to a recovered, unstable sea mine exploding on board. It happened before they had renamed it. A lot of the debris in the area is probably from the Courage."

"What would be your dream find on this trip? Any wrecks you really, _really_ hope to find?"

Sherlock digs out a photocopy of a map from his pocket and taps his finger on what at first glance just looks like random debris situated in a narrow channel between Isla Fuego and a smaller island.

"This is what interests me the most. A photograph taken by a navy diver points to the debris here belonging to a ship of British build, approximately from the 16th century. We know that Sir Francis Drake scuttled two ships, the Christopher and the flyboat Swan, somewhere in these waters during his circumnavigation voyage. Of course, it is wishful thinking that any of the wrecks here could belong to the Drake convoy, but it's a possibility. Not that many British vessels from that era would have sailed through here, so it's a remote chance rather than a likely discovery."

Holmes opens his laptop and shows him images of the Drake envoy ships.

"Why did they use such light ships? Why not bring a carrack if they had them? Surely they would have withstood more of a battering from the open sea than caravels," John comments.

"The caravelwas a favourite among explorers such as da Gama, Dias and Columbus because it was manoeuvrable, fast and cost-effective. Yes, the carrack was better in a big storm, but for approaching treacherous coastal waters or dodging attacks from angry locals, you'd want a caravel."

He opens a book he pulls underneath his laptop and shows John an image of Christopher Columbus' vessels. "You are partly right, though: for his first voyage, Columbus assembled one carrack and two caravels."

John cracks a smile. Getting to talk about things which he is obviously keen on and not just because it's his job, some of the aloofness has evaporated from Holmes, and an almost boyish excitement is now evident on his features. He looks younger, less troubled.

This is the excitement John sees in his fellow divers daily; for Sherlock, only the history and science seem to bring it forth. Clearly, he wants to be here.

John points out the narrowness of the channel between Isla Canoa and Isla St Joseph de Betancur. This is where Andrew had told John Sherlock wants to head in the afternoon. Just at the entry to that channel lie the bits and pieces of what could be a ship that Holmes is interested in. "Depending on the wind and the tide, that current could go up to three knots. Does Dionisio have any idea what the bottom is like? Reef hooks possible?"

Holmes shakes his head. "Sandy bottom, and we are _not_ hooking onto potentially priceless historical wreck debris."

"I'd do this late in the afternoon, before the tide, and definitely not during a northeasterly wind. A northwesterly wind would probably weaken the current nicely in the direction of the channel."

Holmes looks disinterested. "You can look into all that, then."

"I'm just trying to make sure you can get a good look at all that instead of getting swept out to sea," John says and hates his defensive tone. They will both have to accommodate each other's roles: John is the one tasked with making the diving as easy and safe as possible, and Sherlock is the one to point their noses in the direction of the most promising sites.

"That's what you're being paid for, yes." Sherlock downs a third of one of his coffees in one big swallow.

"I'm not on this trip to pay my bills. I'm here because it sounded like a thing I'd want to do. Judging by what I've just heard, that applies to you too."

Sherlock's eyes snap up to meet his, and there is a strange melange of surprise, suspicion, confusion and interest in his gaze. John can tell he's put the poor man off-kilter by John's acknowledgement of the obvious: that he loves what he does, and it _shows_.

"Is this part of some tiresome pep talk you give to all you teach?" Sherlock has regained his distance and his composure.

"No, this is a pep talk I only give to people who I think need it. Who need a reminder why they're here. I think the stress has been getting to you and making you forget why you do all this."

Sherlock is holding his coffee mug in front of his mouth, but John can see the narrowed eyes as the man tries to come up with a reply. "I'm going to talk to Jose-Perry about a mooring site and see Dionisio about the currents. Once I know more, I'll let everyone know what my suggestion for a dive schedule is."

John stands up. "You do understand that all I want is for this trip to be a success, and for everyone to return from it happy and alive?" _I also want to see your face when you find Drake's caravel. I want to make that happen._

Sherlock pushes aside his papers and watches him for a moment.

"I do, John."  
  
  
  


**Notes for the Chapter:**

> Plenty of factors can raise your risk of decompression sickness: dehydration, fatigue, diving on consecutive days, making very deep dives with a short off-gassing period... The dive computer programs and dive safety tables are based mostly on army research, and they cannot 100 % guarantee that a user who stays well within the safety margins won't ever get bent. If you do develop severe DCS, it should be tested whether you have an open foramen ovale (oval hole) in your heart, and it's kinda contraindicated to continue diving even if you have normal anatomy. DCS can be just a mild-nuisance easily treated with hyperbaric oxygen — or it can insta-kill.  
> BSL = British Sign Language
> 
> [Info on historical sailing ships.](https://www-labs.iro.umontreal.ca/~vaucher/History/Ships_Discovery/)
> 
> The wreck discovery they make in this chapter was inspired partly by [this article](https://www.bbc.com/news/world-europe-45630260). 
> 
> Yup, that's how you fix a diver's cramp: grab the tip of your fin and try to straighten your knee. Massage always works (also for plot purposes). Cramps are annoying and can be painful.
> 
> The chapter title comes from Florence + Machine's song ["Never Let Me Go"](https://www.youtube.com/watch?v=zMBTvuUlm98) which is a beautiful and haunting song about surrendering to the ocean. 
> 
> _Looking up from underneath  
>  Fractured moonlight on the sea  
> Reflections still look the same to me  
> As before I went under  
> And it's peaceful in the deep  
> 'Cause either way you cannot breathe  
> No need to pray, no need to speak  
> Now I am under  
> Never let me go, never let me go_
> 
> _And the arms of the ocean are carrying me  
>  And all this devotion was rushing over me  
> And the questions I have for a sinner like me  
> But the arms of the ocean deliver me_
> 
> _Though the pressure's hard to take  
>  It's the only way I can escape  
> It seems a heavy choice to make  
> But now I am under, oh  
> And it's breaking over me  
> A thousand miles down to the sea bed  
> I found the place to rest my head_


	7. Unearthing The Past

John spends the next few days battling boredom as the Oxford team combs through what seems like every square inch of silt in the cog wreck site. As important as the find is, John wants to see more, to dive more, to see some of the bigger wrecks which speckle the sea bottom around the archipelago. Greg is also getting antsy: the cog's historical significance does not change the fact that it is hardly a very breath-taking site for the average Brit sitting on their sofa with a bowl of crisps wanting to see exciting underwater wreck adventures.

There is one on board for whom the novelty of the Graveyard discovery does not seem to wane at all: Sherlock. Even Mariza, collecting their dinner plates, comments that the professor looks like a child in a sweet shop as he is sketching something on the back of a topographical map, talking so fast that probably not even Andrew can keep up with his deductive leaps and analytical details.

John has made himself useful on their Graveyard dives by assisting Joseph with his biological sample-taking. The Frenchman does not make a fuss about himself, but having sat next to him for the past few dinners, John has learned that, as a boy living in the small town of Arcachon by the Bay of Biscay, he had spent his free time collecting sea creatures into pots and pans filched from his mother's kitchen. Even though Joseph's work mostly concerns very small organisms and plant life, he has near-encyclopaedic knowledge of species he has encountered while diving and he is a good storyteller. Tonight, John has enjoyed learning, among other things, about the mating rituals and the parthenogenetic births of bonnet sharks. Before joining Sherlock's team, one of the research groups Joseph had worked for had tracked the migration patterns of manta rays. John grabs a beer while Joseph fetches a glass of white wine from the bar upstairs, and they sit in the sofas close to the dinette and watch two rays swooping around catching plankton into their gaping mouths in the aft underwater lights of the boat.

"No wonder historical sailors think they had seen monster," Joseph points out when a manta does a somersault close to the surface.

"I read that they're practically flat sharks," John replies.

Joseph frowns in that thoughtful way of his. "They are both cartilaginous fish types, subclass _Elasmobranchii_ , but that is divided in _Selachii_ which is sharks and _Batoidea_ which is rays. They are _les cousins_."

"How'd you meet Professor Holmes, then?" Joseph and Sherlock seem to be the same age.

"Centre Camille Julian of Université Aix-Provence. It is a maritime archaeology research unit. He was doing some work for his PhD, and I was also doing research there." 

John knows that Marseille is the main port of France, has lots of shipwrecks in its surrounding waters, and the headquarters of the French Department of underwater archaeological research, DRASSM, is located there. The department had once engaged John's services in planning and implementing the dive safety protocols of the raising of a Roman shipwreck in Antibes on the French Riviera. It had been a wonderful summer. John had had a fling with a thirty-something Italian postgrad student named Alessandro––

"Sherlock's mother is from Montpellier. He spent summers as a child in the region, with his mother's parents," Joseph interrupts his train of thought.

"Oh," John replies, surprised at this sudden bit of personal information. Suddenly, a whole host of possibilities opens itself up of picking Joseph's brain about stuff Sherlock wouldn't volunteer. "How was he… what was he… so, you were work friends at the Centre?"

"I'm not sure if… friends. He kept to himself. But maybe I know him a little bit."

"I imagine he's not easy to _get_ _to_ know."

" _Petit a petit, l'oiseau fait son nid_. You seem to be good at that."

"Sorry, I don't speak French."

"Little bit by bit, the bird makes nest. I believe the English say Rome was not built in one day."

"I assume French is one of his twenty-three languages."

"I think he spoke it with his mother. You cannot tell he's not a native speaker, except for accent. He sounds very English," Joseph chuckles.

John imagines Sherlock's baritone of caramel-drenched mahogany forming words in French, and has to suppress a shudder of delight.

"I wonder why the BSL, though."

" _Excusez-moi_?"

"British sign language. He must have learned it for diving, but why? Wouldn't be very useful if his diving partner didn't speak it."

"Oh. No, no, he learned it as a child. For his mother."

"But I thought you said she spoke French with him?"

Joseph shrugs. "That's all I know. I didn't ask more. He didn't want to talk about himself. Maybe he also would not like me telling you these things."

_______________

The next morning, instead of the boat bobbing like a sitting duck on the small waves in the Graveyard lagoon, the engines are on when John wakes up, and the hull is shaking from larger waves.

He wastes no time in getting up, wanting to find out why they're on the move. He finds Sherlock on the dive deck, assembling his isolation manifold. "I reviewed most of our overall data for the cog survey last night, and I believe we have what we need from that area," he explains, grabbing on to the back of the bench as the boat hits a higher wave.

Behind them on the starboard side looms the hulking mass of the volcano on Isla Fuego. Even dormant and covered with lush, green vegetation, it's an ominous sight. Seagulls are nesting on its steep flanks, which drop into the ocean as dark grey, vertical basalt cliffs. They are no longer sheltered from the open ocean by surrounding islands; here, waves which may have travelled all the way across the ocean crash against the basalt columns violently, breaking into a spray which occasionally lands on John's arm where he stands close to the dive platform.

Sherlock flashes him a grin. "Ready for something bigger, then?"

The more days pass, the less troubled and withdrawn the man seems. He has his bad moments and bad hours and bad days, but he's clashing with the others much less now.

John refrains from commenting that he's been ready for days, for something a bit more demanding than faffing about on a shallow sandy bit. "What's on the menu?"

"I told you about the USS Courage, didn't I?"

"Yeah."

"Turns out there is an even larger minesweeper-destroyer hidden in these waters. I hadn't connected the dots before — possibly because the Guatemalan navy likes changing ship names frequently and sometimes even their chroniclers have got a bit mixed up what the original version was called. The Courage would have made for some nice footage for the BBC, but it sank barely twenty years ago. Boring; hardly qualifies as archaeology," Sherlock sniffs. "However..." He digs one of his notebooks out of his shorts pocket. "Say hello to the USS Bainbridge." He gives John a folded piece of paper.

It's a photocopy of an old schematic of a ship — a large one. 'Wickes-class', it declares, and the year on it is 1918. There are two radio masts, four chimneys, two geared steam turbines, 96 metres long. It's a swimming fortress.

"Maximum speed 65 kilometres per hour, displacement 1.25 tons with a full load. Ninety have been scrapped, nine sunk in battle, five sunk as targets. Seven others have sunk or been destroyed in other ways. The Bainbridge was assumed to have sunk in a storm after being structurally weakened by battle. It disappeared off the radar off the Mexican coast and was never seen again. I combined the data the Guatemalan navy has assembled—they've actually done training dives to a wreck I suspect is the Bainbridge, but they never penetrated or made a note of the name—and compared it to all the Wickes-class schematics I could find. All other ships of that class are accounted for. I was hoping to verify the wreck's name and to penetrate it."

"What depth are we talking?"

"Sixty-three metres."

"You couldn't have told me a bit sooner? A tec dive requires a bit more planning time than 'have some breakfast and then we'll drop down', you know." Sixty-three isn't particularly excessive, especially not with John's experience, but it'll be their first tec dive together. The fact that they will enter the wreck also requires additional planning of how to streamline their equipment, how to delegate tasks of reel-laying and such…

"I've created a plan which I will share with you over coffee. As a seasoned professional, I assume you don't need all that much time to learn the details."

 _Why am I surprised he made all the plans alone?_ "Where is the wreck?"

Sherlock leans over the railing and gets the front of his long-sleeved white T-shirt splashed by a breaking wave. "We should be arriving at the site in half an hour. The rest of the team insisted on having breakfast first. Time-wasters," he grumbles.

"Breakfast sounds good. After I get some of Mariza's eggs, I'll penetrate anything you want."

_______________

After verifying Sherlock's gas calculations and the dive plan he had devised, John is pleasantly surprised. It is conservative, safe, meticulous and pretty much the way he would have planned it. It details not just gas consumption and consequent supply needs, but also a list of gear needed, plans for maximum penetration time, maximum depth, decompression protocol and additional safety stops and path-marking procedures. John is positively surprised at the level of scrutiny Sherlock has given to the safety margins. Divers entering overhead environments tend to adhere to the so-called rule of thirds: a third of their gas supply will be used on the outward journey, one third for the return, and the final third is contingency.

"How do you have my gas consumption numbers?"

"You have them on your iPad."

"My iPad's locked, you berk."

Sherlock gives him a derisive look. "'Password' is not a very secure password."

"No, but why would anybody ever guess that it would be that stupid," John defends himself.

"Not everyone underestimates the stupidity of the average idiot," Sherlock says with a shrug.

"Oi! I'm not an idiot!"

"No, no, don't be like that; practically everyone is."

John should be insulted, but Sherlock has made his statement with such unflappable, misguided conviction that he finds himself laughing, instead.

"Is my plan acceptable, then?"

"Yes. But next time, I'd like to have some input."

"Why? My calculations are accurate."

"Yes, but you know, partnership and all that?"

"Why waste both our time on something I can do on my own?"

John stares at him, then decides to pick his battles. Instead, he goes to make sure they already have all the tanks they'll need. "Who else is coming with us?"

"No one. Anderson's ear's acting up, and Morten and Joseph are surveying the Isla Fuego fringe reef."

"Greg's got to be having kittens." Their main underwater cameraman having trouble equalising his ears is a major threat to the documentary. On yesterday's second dive, Anderson had been unable to equalise his left ear but since he didn't seem to be developing flu symptoms, John had assumed it was just a minor hitch that would fix itself with some rest.

Sherlock's plan details Dionisio as a safety diver, meaning that he'd get into the water if someone needed assistance. Keeping him on the surface would give him the most bottom time in an emergency since he would only go down if needed.

"I promised Lestrade you'd carry a GoPro," Sherlock announces.

"Alright." _Of course, he'd volunteer my services without even asking first._

In addition to two tanks of trimix, they will both carry one nitrox tank, one compressed air tank and one small 100% oxygen tank to speed up their de-gassing at their last decompression stop. Most of it will have to be lowered into the water and clipped to their wing plate rigs with air bladders once they've jumped in and are floating on the surface. The tanks will also be lifted out of the water before the divers can exit at the end of the dive; no one could ascend the boat ladder with four tanks weighing nearly 50 kilograms.

________________

"So, John, could you explain why entering sunken wrecks involves greater risks than open water diving?" Greg asks.

Anderson's camera is pointed at John, who's standing on the mid deck leaning against the railing with Isla Ruina as a backdrop. A clicking sound heard in the background signals that the anchor is being lowered. Soon, they will dive, but first, John had promised Greg a few minutes for an interview for the documentary.

"Whenever you're in an overhead environment, you can't just start surfacing if there's a problem. You have to have enough gas to get you out of the wreck and _then_ back to the surface. You can get lost and disorientated when moving around wrecks, especially because you're not just walking around — there's up and down, too. Wrecks tend to gather layers of silt, and a fin kick could puff all of it up, and that can bring visibility to zero in an instant. That's why you have to lay a line from a reel which you can use to feel your way back to your entry point if need be. This is what untrained, inexperienced divers don't realise when they enter wrecks without proper training: that even though you can see where you are now, that might change very quickly in a silt-out. You also need dive lights for obvious reasons: without ambient light, it's going to be pitch dark inside a wreck."

"And obviously wrecks don't stay in good condition if they've been down there for a long time," Greg prompts.

"Metal rusts, things can collapse and shift, there can be sharp edges and hanging wires. You have to be mindful of your gear when squeezing through narrow spaces. Wrecks are often covered with fishing lines and nets, and many divers have become tangled up in those; you need line cutters and a diving knife with you."

"What about unexploded ordnance?"

"Warships might have that, yeah," John confirms. "But the most common things that kill diver during wreck penetration are the same stuff that kills divers anywhere: panic, disorientation, crap gas management, rough surface conditions, narcosis, inadequate training."

"There's also the fact that this will be a deep dive."

"Yes. Deep enough that we can't come straight up after we're done: we have to make stops are different depths to make sure our bodies can get rid of dissolved nitrogen gradually and safely. We will use different diving gases at different depths to either prevent nitrogen narcosis and oxygen toxicity or to speed up the off-gassing process."

He refrains from going into too much detail about the equipment such as choosing double tanks with isolation manifolds versus independent doubles with separate regulator systems. He's glad that Greg is considering featuring stuff about diving safety; too many bad films and common misconceptions lead to people who have no business entering wrecks just going for it and getting into trouble. John has hauled the bodies of several such daredevils out of wrecks or investigated such lethal incidents for insurance companies.

"Hey, Holmes?" Greg hollers; the professor is making his way down the steps, wetsuit already on as usual. "We're rolling; could you tell us that story I overheard you telling Morten yesterday?"

Sherlock's expression is a very pained version of _must I_ , but he does join John by the railing and clears his throat. "You want me to look into the camera?"

"Sure, yeah."

"Right. The thing about the _Abraham Crijnssen_?"

"It had some wonky name like that, yes."

"It was a minesweeper of the Royal Netherlands Army, which found itself separated from the three other warships it was supposed to sail with as they were ordered to withdraw from the Java sea to Australia. To avoid being detected by Japanese aircraft, it was heavily camouflaged with jungle foliage as a small island. To further the illusion, they remained close to shore, immobile during daylight, and would only move at night."

As he speaks, John shifts away from the frame so he can watch the man. He would have probably insisted on wearing normal clothes if Greg hadn't just grabbed him like this, but the wetsuit adds something to the shot, doesn't it? It's certainly a sight to behold; the lithe, compact lines of Sherlock's stunning body held in bondage by tight, black neoprene. Chin tipped up, curls whipping around in the sea wind, he looks unattainable and statuesque, and John can't get enough of the sight. _I can look, but I can't touch. Shame._

"Did they make it to Australia?" Greg asks off-camera.

"This disguise was successful, and the Crijnssen arrived safely in Fremantle in March 1942. It is now a part of the Dutch Navy Museum at Den Helder. Now, if you'll excuse us––" he grabs John's wrist and pulls him towards the stairs. It appears Sherlock has fewer qualms about physical contact as long as it's him initiating it. _As long as it's about business_.

"There'll be plenty of time to bask in the bloody limelight later," Sherlock complains to John, dragging him to the bottom deck. "Right now, we've got diving to do."

  
_______________

"John, could you––"

"Let me––"

They both trail out; Sherlock's sea glass gaze merges with John's. The taller man's dive computer has snagged on the strap of his wingback BCD, and John was just about to warn him that he was going to reach out and fix it when Sherlock had taken a step backwards with the same idea. Upon hearing John's voice, he'd turned to look at him.

John flashes what he hopes is an easy, disarming smile, his hand hovering above his shoulder. "I hate it when that happens. If I don't have anyone to give me a hand, it feels like being a turtle stuck on its back."

"Quite," Sherlock rumbles quietly, then turns sideways so that John can lift the strap over the computer on his forearm. "Thank you, John."

He sounds awfully formal, and John doesn't know how to go about changing that. "You sure I can't convince you to have a go with the radio system? I promise you I won't start singing sea shanties in your ear."

"You're not supposed to introduce alien gear on a deep dive," Sherlock reminds him, and he's right. Even just communications gear could disturb focus. "I've never equalised a full-face mask."

"Right."

They're now standing face-to-face, and this time, Sherlock does not protest doing a proper reciprocal gear check. Every regulator, every strap, every piece of equipment that they might need to access to assist the other is inspected, and their function tested together. A final, verbal review of the dive plan is done in a rapid-fire manner by Sherlock. He sounds very business-like, and his expression has gone rather sober.

"Nervous?" John asks.

"Define nervous."

"Well, there's good nervous which is just preparing for a demanding task, and there's bad nervous which is fear and a sense of foreboding, I guess."

"I don't believe in foreboding."

"Of course. you don't, and that doesn't answer my question."

"Good nervous?" Sherlock offers. "Anticipatory."

"Glad to hear it. No point in doing it if it's as boring as sitting on the sofa. Oh, hold on." John reaches out to tuck some unruly curls inside Sherlock's hood. At depth, it'll be colder, and for someone whose hair is a thick mop like Sherlock's, it's easier to strap on a mask and to adjust it if those dark locks are safely trapped inside a neoprene hood. John is wearing one, too, and they will add gloves to their ensemble before jumping in.

As John's fingers approach Sherlock's face, there is the tiniest retreat until Sherlock yields, exhales and lets his flashes flutters at those fingers make contact. He's watching John carefully, skittishly.

"Perfect," John says and steps back to lean down and grab his fins. _All of you_ , he finds himself thinking and chuckles inwardly. No harm in liking what he sees, and long as he stays polite about it. Being shot down at his very first advance at the port bar has stripped him of urgency to get things moving forward. Now, discreetly, he can relish these moments.

"If you're done with your _visual survey_ ," Sherlock comments pointedly, "we can get moving."

John's lips spread into a grin. _He knows_. _It's up to him what he does with that knowledge._

Perhaps that grin is a bit too audacious for Sherlock's taste because John can practically see him tense up, grow distant, slam up barriers.

 _I wish he didn't feel like he has to be so careful with me_. Or is it about him, really? Maybe Sherlock is like that with everyone. But why would he dress and groom himself the way he does, if it's not an invitation for attention?

 _But what if it's armour-plating, instead?_ Sherlock never changes clothes in front of others; he changes into his wetsuit in the privacy of his cabin and drips water all over after each dive when he makes his way all the way back there to change out of it, which probably irritates the staff. He's quick to become apprehensive or even aggressive when someone expresses their interest. 

_What if my radar was completely off, and he's not gay or bi?_ If that was the case, wouldn't Sherlock have said so instead of the way he dismissed John's advances? _No_ , John decides, _I don't tend to get these things wrong._ He can't convince himself that homophobia might be a reason for the man's behaviour.

 _The big picture here just doesn't make sense_ , he thinks as he makes his way to the edge of the dive platform. He inflates his wing, lifts his feet so that Dionisio can help his fins on, counts the tanks that will be lowered to him in the water one more time, then puts his reg in his mouth and jumps in, holding on to it and the mask.

Seconds later, he surfaces in a whirl of bubbles and finds his partner. They receive their tanks, adjust their gear, and then begin descending. The moment of leaving the atmosphere and sinking down still gives John a mild but exhilarating sense of excitement, and he consciously calms his breathing and focuses on equalising his ears and his sinus system as he descends at a slow rate. Two metres away, he watches Sherlock do the same: a form in black against the blue, he has crossed his ankles as he sinks, feet first, the fingers of one hand pinching shut his mask-enclosed nose, the other watching his gauges.

They exchange OK signs, rotate around their vertical axis to see if there are any sea creatures worth watching as they make their way down, down. John hears the hiss of his exhalations, the clicking of dolphins somewhere close by, and the distant rumble of the boat engines mixing with what sounds like sand being ground against plastic; he has never quite identified what produces it, but it's a frequent aural sensation in the vicinity of vessels.

Light bends in the water, forming crystal-shaped pillars which seem to point down like a runway in the ocean. Twenty metres deep, now. Then thirty. No current.

At forty, the visibility is so good that they begin seeing the outline of something dark far below. It's just a shape, a shadow; variations in dark blue. Sherlock points down, then cups his hands upside-down to signal _wreck_. John nods. Dionisio and the captain had done an excellent job in locating it and finding a spot where they wouldn't have to do a long swim near the bottom to the structure.

At fifty metres, the shadows merge into a ship. It lies on its side, a gaping hole in the middle. John's heart leaps into staccato at the sight of it: _did something hit it, or has a part of the hull just collapsed as the metal has corroded and disintegrated?_

Sherlock's plan had been to find an entry point on the main deck, but this hole will allow them to save time since they can penetrate into some of the key staff areas and weave in and out or different floors. But first, they must verify the name of the ship.

Once up close, the ship no longer looks like a ghostly Flying Dutchman of the sea bottom but a less frightening human structure of metal and glass. They find a good buoyancy and Sherlock leads then along the edge of the top deck to where they would expect to see a name. Unfortunately, corrosion and barnacles have erased whatever had been painted on the side. They'll have to find other clues about the identity of this carcass.

  
_____________

On close inspection, the wreck is almost split in two in the middle, the edges of the gaping hole in the hull twisted inwards at spots and in every which direction elsewhere. There is nothing pointing to a directional impact with a large object — instead, it is starting to look like something has exploded against it.

Sherlock comes to the same conclusion, making the explosion-symbolising gesture of his fist opening very rapidly. John nods.

After inspecting the damage, they turn on their primary dive lights, and John prepares a reel of line he will lay in as they penetrate so that they can find their way back to the open ocean even in a silt-out. Laying a line requires training: it should be done in a way that prevents the divers from tangling themselves in it. John has a free-running reel with a lock which makes it easy to pause before taking on the next section without the line unspooling from the reel. He uses P-clips, also known as boltsnaps, to attach the reel to himself when he's not using it. Unlike spring clips which are commonly used to attach diving equipment to one's BCD, boltsnaps can't accidentally swallow a line around which they're clipped and consequently make it come loose. John prefers a thicker line than many other divers; it's more resistant to abrasion and handles better with the thicker gloves he needs for the cold depths on particularly deep dives.

Even just following a line requires training, too. Physical contact with the line must be maintained constantly with the right grip — just forming a ring between the thumb and the first finger is not enough; one needs to use three fingers. A hand must never be removed from the prior section of the belay before the next section after an anchor point has been found. John prefers removing the line as he traces his way back out of a wreck because he doesn't like leaving anything in that doesn't belong there. Some divers just cut the line and follow it back.

In the first rooms they survey, there is still plenty of sunlight since the explosion has ripped apart the bulkheads forming some of the inner walls. There's plenty of silt in these areas since the ocean has been able to carry it in freely. Fish swarm lazily around them.

Sherlock has already been jotting down copious notes on his stack of writing slates in tiny handwriting because the space on the white, plastic things is not unlimited. They find the remains of the engine and presumably the ship engineer's office, judging by the artefacts there. Sherlock seems to have little interest in the machinery that has powered the ship; instead, he heads towards the back of the ship and on a higher deck; John assumes he's looking for things such as crew quarters.

A narrow passage where they have to fin forward in single file takes them through what has clearly been a washroom. It's completely dark, now, and large bits of silt are floating in the cones of their dive lights. Only a few shyer fish have taken up residence deep in the bowels of the wreck.

It's far from quiet, though. They can hear metal groaning, air bubbles shifting. It sounds like echoes of the final agonised breaths of a warship. They also mean that the integrity of the ship is likely compromised not just by the explosion but by years of being at the mercy of the eroding forces of the ocean.

The next area is larger, and it's easy to recognise chairs and tables even when they are in disarray. They must have been tossed around as the ship sank. John wonders if it had been a drifting sea mine which had brought it down.

Sherlock stops abruptly barely inside this area — likely the mess hall — which makes John bump against a chair. He doesn't mind; Sherlock couldn't see where he was since he was in the lead and the corridor from which they'd emerged had been narrow. Now, they have ambient light once again from the small, round windows on the wall. They still keep their torches on since their light enhances the colours of everything. Deep down, colours are always dulled down and then disappear in the order in which they appear on the colour spectrum. Even at just a few metres of depth, the colour red is gone.

They start inspecting the scattered items on the floor. There are metallic plates which were likely used by crewmen, and pieces of broken porcelain pieces from what might have been the officers' plates. Sherlock grabs his arm and shows him a large piece with a word painted on it: _Bainbridge_.

They share a grin — it's just as Sherlock had suspected.

John is still riding the high of the discovery when Sherlock's expression sobers and shifts into a frown. He'd let go of John's forearm, but now, he grabs hold of it again, pushing it up so he can see the triceps side.

Blood that looks blackish in the low light is bursting out of a cut in his wetsuit sleeve. It's easy to ignore a cut since wet, cool skin pressed under neoprene has much less feeling. The blood is trickling out at a rate that cannot be ignored. John glances back towards where they'd come and pointing his light at the toppled chair he'd bumped against, he notices how sharp the edges of its legs are. _Fuck_. _Do we have to abort the dive?_

Sherlock is rummaging around the utility pouch clipped to his wingback BCD. Soon, he produces a safety pin; the spike part of it has been bent to the shape of an arc. John assumes he's going to use to tighten the sleep back around his arm but instead, Sherlock grips his arm hard, and drives the arched spike through the edges of the cut, then snaps it shut. It's still oozing a bit of blood from the edges, but not bleeding copiously.

John gives him a look where awe mixes with anger. _I'm supposed to be the bloody physician on this trip._ Sherlock lets go of his arm and shrugs, and John inspect what he's done: it looks good. He digs out one of his spare neoprene patches and a spare rubber fin strap and uses it to tie the neoprene patch on the wound. They use Sherlock's torch to watch how much blood is trickling out from underneath — none at all.

Sherlock points towards where they'd been heading, then points his forefinger up and then makes an "I don't know" gesture. _He's asking me if we should go up or continue_ , John realises. John points resolutely towards the back of the mess hall.

Sherlock takes the lead again, and the next room they discover is the scullery. More dishes there, many of them intact, offer further proof of the ship's name.

They check their gauges just as they have frequently been doing throughout the dive. They have about five minutes before their plan dictates that they start heading back. There's a forking corridor leading to crew berths which they circulate and find another large space on the starboard side of the ship. Going through it should take them back to a twin corridor which had led them in from the engine area. They spare a few minutes to examine a couple of small cabins. There are skull fragments in one of them; all flesh has been eaten by sea creatures. John is glad of the GoPro screwed onto the front of his large twin trimix tanks; no need to allocate time for snapping photos when everything he is seeing and experiencing is being recorded on video.

Books and clothes have largely disintegrated in the long, dark years on the sea bottom but there are other kinds of personal items which offer points of interest. It's clear from the richness of the artefacts that this ship has not been penetrated many times, if ever. John wonders if the Guatemalan navy frogmen have had the requisite gear that would have enabled them to venture in.

A slightly larger cabin features the remains of several books, some epaulettes, metal bits from pens. There's a locket — perhaps a memento from a sweetheart — the photograph inside of which has disintegrated. The leather straps of a watch are gone, but the round, glass-covered mechanism is still intact, permanently frozen at a quarter to four.

John lifts a bottle out from underneath the bunk — there had once been whisky in it, but the cork is gone, the contents scattered into the water. A crab is residing in the dark recess-like shelf behind the bunk inside a toppled jar which had probably been used to store things.

John taps Sherlock on the shoulder and points at his wrist. _It's time to go_.

With a nod, Sherlock follows him out of the cabin which had felt quite cramped with two divers hovering inside.

They find John's line as they make their way towards the middle of the ship; they have circled around a corridor. This will save us some time in getting back.

The port side aft engine room requires some careful finning around twisted metal and furniture as they try not to disturb the ocean floor muck. They'd made their way in through a twin room just on the other side of a bulkhead and assumed that this one would be cut open by the explosion, too. This turns out not to be the case.

They're just about the turn back when a loud groan and a bang reverberate through the ship. There's a rumble, and then silt begins spreading from the adjoining corridor into the room behind the engine room at an alarming rate.

_A cave-in. Fuck!_

The room they're now in is large enough for them to be side-by-side, and a porthole with a broken glass offers some dark, green daylight just before the silt covers everything. John had set an auxiliary line back to the intersection that had ended their round of the ship, but as he feels around in the doorway to that room, he finds that god-knows-what, disturbed by a current or perhaps just their finning had, has fallen and blocked their path. It could be a part of the round staircase John remember from the corridor. His line is useless since it's buried beneath rubble now, too.

Some hard tugging tells him there's no way to remove the obstacle, and the opposite way had been shut, too.

 _Don't think about it,_ he tells himself. _Don't let the words form._

Not even their dive lights are any help, now, as the silt blocks out even their light. John turns back and feels around; he knows the room is square, about three metres by three metres.

It doesn't take him long to find Sherlock, who is hovering patiently in the middle. He'd probably positioned himself there deliberately so that John would be likely to find him fast. John finds an arm, is relieved to find it motionless and grabs his partner's hand. Sherlock gives him a determined squeeze.

 _Nobody's panicking. That's good. That's very good._ They have plenty of gas left; John is still on the first of his twin trimix cylinders, and Sherlock had used his isolation manifold valves not five minutes ago to swap to his second. He'd been darting around, inspecting the contents of the ship much more actively than John, who always likes to keep his movements economical and well-planned. It seems that Sherlock's enthusiasm cannot even be contained by tonnes and tonnes of water upon them.

They run their palms around the room and find the porthole. A few minutes of waiting clears the water enough that they can see the faint green shining through the round hole. John unclips his diving knife from the strap on his ankle and uses the handle to make sure no glass bits are sticking out of the edges.

Sherlock digs out a reel, uses it to take a measure of the round, glassless hole. He then measures out a double length of that measurement and wraps it around his and then John's shoulders. Both fit snugly inside the reel look.

With John's dive light pointing upwards between them, they press their masks together and share a look — they have to communicate at very close proximity because of the silt-out.

No words are needed; Sherlock's measurements have told them everything they need to know.

 _We can get out_. John gives a nod that is not yet triumphant but hopeful. Sherlock's pale, sea glass eyes shine with determination.

 _Won't be easy, though_. They will have to disassemble their tanks from their BCD and push all pieces of equipment through one at a time before squeezing their bodies through. This is where knowing their kit by heart and being familiar with their partner's is important: knowing where the straps and valves are making the challenging feat possible even half-blinded by the silt.

Once they have all their regulators with the attached tanks and their other gear bunched together, it's time to go through the porthole.

John is the first out. The regulator hose to his trimix tanks is long enough that he doesn't have to push through feet-first. His hips require a bit of wriggling and grunting, but finally, he's hovering outside the ship. A look around shows that they are exactly where his mental map had placed them — not far from the hole ripped by the explosion. He receives his other tanks and his wing plate with the air from its bladder completely emptied and reassembles his kit. Only after he feels the reassuring weight of the straps on his shoulders and the snug fit of the belt around his hips can he drop out of battle mode.

Not completely, though. Sherlock is still trapped inside the wreck, and John needs to be calm and helpful to give him the best chance of getting out without any trouble. Sherlock pushes out his tanks one by one and waits while John clips them into a loop on his waist to keep them from falling onto the ocean floor. His wing plate comes through and finally, the man himself pushes through the porthole head-first. John gives him a bit of a tug by the lapels when his shoulders get briefly stuck. Once the shoulders slip out into the open ocean, the rest of him follows. John wraps an arm briefly around his shoulders in relief, then helps him reassemble his equipment.

John feels shaken but not panicky, and Sherlock appears to be coping well with what they've just been through. Stress and panic can happen to anyone; managing them is key. John had been astonished to discover early into his diving career that it's possible to be aware of panic attempting to take over yet remain completely functional. Maybe the same ability had helped him in his days of manning A&E departments at London hospitals. Good divers are not immune to panic — instead, they recognise the danger of it and know how to stop that vicious spiral before it compromises their ability to use the skills, experience and training they have amassed.

They both still have plenty of gas left, so they make a swim around the entire ship before preparing for the ascent. John watches his partner like a hawk — sometimes the stress of an adverse event hits with delay and can incapacitate a diver's ability to function and think logically. But, to his positive surprise, Sherlock seems to have shrugged off the whole thing.

 _We did just almost get buried alive forty fathoms deep_ , John finally dares to acknowledge. _At the Torres dive site, he looked ready to bolt just because we had some current and saw some sharks. Now, he's fine. Whatever troubled him on that first dive clearly isn't a consistent issue connected to the diving itself_. _Maybe he was just jetlagged and nervous about diving with a new group._

At the precise time they had agreed to start their ascent, Sherlock stops finning around the aft cannon and approaches John. They begin a slow swim upwards, keeping an eye on the ascent speed indicators on their dive computers. They should rise slower than their bubbles do to prevent gases from bubbling up inside their bodies. Once they're at twenty-five metres, they swap to their nitrox tanks to speed up the removal of the nitrogen. They have four decompression stops to do, which makes their planned ascent time thirty-seven minutes. All of these stops go without a hitch. Sherlock mostly spends them by hovering with his ankles crossed, making the odd note on his writing slate, occasionally glancing at his computer. Passing sea creatures offer some entertainment during these long stretches in the otherwise endless, empty blue. For their final, short stop, they swap to 100 % oxygen. It gives the finishing touch to the below-the-surface part of their off-gassing, and always seems to clear John's head of tiredness, gives in an extra boost of energy for the arduous process of disassembling, examining and maintenance of his tec equipment. Computers need to be rinsed of saltwater, the bladder of the wing plate emptied of water, every bit and bolt examined for wear and tear, tanks swapped for full ones…It's as important as the pre-dive check, to make sure that the equipment is in good order before being stored.

John is the first to climb out after Dionisio and Greg have lifted most of his tanks out of the water after he'd unclipped them.

"How'd it go? Did you get any good footage?" Greg immediately asks as he offers John a hand for clambering onto the dive platform.

"Bloody rust bucket trying to cave in on us. I'm sure your viewers will get a kick out of that," John scoffs, but he's wearing the smile of a tec diver out from a very adventurous trek. This wasn't the worst pickle he's been, not by far.

"What was it?" Andrew asks, sidestepping as John threatens to get him wet as he's taking off his wetsuit.

"It's the Bainbridge, just as I thought," Sherlock confirms, stepping from the dive platform onto the back deck. "There's some fantastic stuff down there, but the integrity of the hull may prevent full exploration. I'd send drones, especially considering the depth."

Morten appears on deck and starts helping John carry the empty tanks to the gas blending area.

"How'd he do?" The Swede asks in a low voice, glancing towards Sherlock to make sure he's not within earshot.

"Just fine. No panic, not even when we had to come out through a porthole."

"That's good. Does that mean you'd do even deeper dives with him?"

"I can't see why not."  
  
  
  


**Notes for the Chapter:**

> To summarise, the key differences between regular recreational scuba diving and tec diving:  
> – scuba divers use air or air mixed with oxygen and generally stay at depths shallower than 40 metres  
> – scuba divers don't need decompression stops/staged decompression at the end of a dive; if need be, they can slowly ascend directly to the surface  
> – tec divers use various mixed gases to be able to go deeper and to stay there longer  
> – tec diving requires sturdy basic diving skills, lots of additional training and lots of complicated equipment  
> – both sensible scuba divers and tec divers have their own dive computers but the tec diver models are, of course, much more complicated  
> – wreck penetration and cave diving can be done by both tec and scuba divers, but the limitations of the regular equipment mean that scuba divers' rec explorations are relatively short
> 
> The equipment you need for a dive to a site as deep as a submarine wreck on Malta at 100–130 metres can be seen [in this video](https://www.youtube.com/watch?time_continue=134&v=owglvMkDgRQ&feature=emb_logo). It wouldn't really be possible (as far as I can tell) to disassemble and squeeze through a porthole this entire set, but for the sake of adventure and fiction, I have bent the rules of realism a bit.
> 
> In this [deep wreck dive video](https://www.youtube.com/watch?v=WdsHEsokFHk) from Malta, it's easy to see how colour disappears underwater and how using a dive light brings those colours alive again.
> 
> [This is what silt-out means and looks like and why a dive light doesn't help when it happens](https://www.youtube.com/watch?v=Cv2XstyyPOs).
> 
> I am posting some fun and sexy graphics with each chapter announcement on Tumblr. You can [follow my Thermocline tag here](https://jbaillier.tumblr.com/tagged/thermocline).


	8. Storm Warning

> _The sea, once it casts its spell, holds one in its net of wonder forever.  
>  _— Jacques Cousteau, Oceanographer

The next morning, the skies hang low and grey, and the wind has died down. One might assume diving conditions could be alright, but Dionisio says that the currents are strong today here between a smaller island and Isla Fuego where they had moored overnight.

"Tropical cyclone warning," Jose-Perry tells John at breakfast. Usually, he doesn't eat with the guests, but today it appears that the weather warrants an assembly. "Lagoon not good idea today, strong current probably from ocean. We should wait this out between Maria Santa Madre and Fuego."

"Visibility's gone to shit," Anderson says. "Somehow, the currents have gone haywire before the storm's even here."

"How's your ear?"

"Alright, I think."

"It might graduate to hurricane status once it gets closer to the continent," Dionisio says. "Out here, we should be alright."

He doesn't seem too worried, so John decides he isn't, either.

Greg trundles down the stairs to the dinette and claps John so hard on the shoulder that the wind is knocked out of his lungs.

"Bloody Christ on Piccadilly Square, John, the stuff you shot yesterday!"

John's brows dip into a confused V.

"Fucking gold, it was! That silt out'll be the cliff-hanger between the episodes."

"Episodes?"

"Yeah. I satphoned Bridgette, says she shouldn't have any problem negotiating us three episodes instead of just one special. Even with what we've got so far, it's a done deal."

"Well, I'm… glad, I guess. Where's Sherlock?"

Greg chuckles. "Posh boy's up in his cabin, preparing; I managed to talk him into an interview. Even though his contract says he has to do it, it's like trying to shove a mule into a fishbowl."

"Can I listen in?"

"If he says alright, sure. What did you do to your cut?"

By the time John had put his gear away and gone back to his cabin, the wound was no longer bleeding even though it was soaking wet under the neoprene patch. He'd grimaced as he pulled out the safety pin — he doubts Sherlock wants it back — and with the help of the vanity mirror in his ensuite, he'd briefly considering using one of the three Appose Ulc surgical staplers he'd brought along but ultimately decided that butterfly tape and some gauze should do the trick just as well. This morning, when he'd changed the bandage, the cut had looked good. It isn't very deep.

"Do me a favour, mate?" John asks Greg.

"Depends on the favour."

"Ask him about how he got into marine archaeology. If you can get him talking about that, there might be a nice story or two in there."

"Still trying to crack the great mystery of Professor Holmes?"

John accepts a cup of coffee from Mariza. "Thanks. What are you on about, Greg?"

"He shot you down, and you can't work out why or get over it, can you?"

John purses his lips. "I just think he's interesting, that's all. Besides, I'm not the one with a problem with handling human connection; he is." He nods towards the direction of Sherlock's cabin.

"You just prefer certain parts to connect and the rest to just… I don't know. Usually, your interest wanes at a certain point if the other party's not on the same page — or wants more."

"That's not all I care about," John complains. He should be angry at such an insinuation — that getting a leg over is all he thinks other people are for, but it's his own fault, isn't it? He hadn't exactly spoken very respectfully about Sherlock at their table on that first night. It's just guy talk, but John is slowly beginning to accept that it had cracked something open in him, being confronted about not the way he really feels and thinks, but about the way he presents all of it.

_You're not what the first impression tells people, are you? Maybe I'm not, either._

At least Sherlock seems to be giving him another chance after that wreck of a start.

"Bridgette thinks you only like her because she's safe; you know she won't really chase after you, try to have a relationship with you. You worship her as long as it's not real."

John puts down his mug. "What are you busting my balls for?! You've managed to keep Molly for a few years, and suddenly you're Mister Relationship Advice?"

"You know we're the same, John — or, we _were_ the same. It'll happen to everyone, that moment when you start thinking that it's kind of sad if all the ships just passing in the night never find harbour. Is he another Bridgette, then? Safe, fun, convenient because you don't have to deal with anything that a proper relationship would entail? I don't want any drama stirred up because it would probably shit on our work in these cramped quarters, but you're a mate, John, and this is also about that."

John picks up a piece of dried-up toast. "He's… I don't know what he is. I don't know what I want. I don't know what he wants, and it's most likely nothing. I'm not trying to get off with him."

"Do you have to know?"

John's nose crinkles thoughtfully. "Don't people usually?"

_________________  
  


Greg and Anderson set up their gear at the narrow sundeck at the front of the boat between the cabin tops of the mid deck. They're anchored between Isla Fuego and Isla Ruina near the rocky shore of a smaller, unnamed island which will offer them some breakwater protection from the larger waves coming in from the open ocean. This position is far enough from the Graveyard lagoon that they won't be affected by the potentially destructive currents coming in through the two narrow straits which have made the spot such a treacherous one for ships. They should be able to weather the storm here if it hits; it's still sunny, but clouds looking like they have been ripped to shreds by giants are swooping past high above them, meaning that the wind in the upper atmosphere has picked up, and blueberry-grey clouds line the horizon in the west.

John, water bottle in hand, sits down on one of the deck chairs to keep out of the way. Anderson has set up a barstool from upstairs in the middle of the deck, facing away from the front tip of the cockpit area.

"How long's he going to take?" Greg asks rhetorically. "We've been ready for half an hour."

"You said it, he hates the interviews, so maybe he's just stalling. Or maybe he doesn't actually intend to show up," Anderson grumbles.

John shades his eyes with the side of his palm and drinks half his water. The horizon looks dramatic with the high-rising, puffy yet ominous anvil-shaped thunderclouds contrasting with the turquoise water around the small island to their left. Here the diving visibility should still be alright, and if the weather stays nice and the current are tolerable, John might dip in with scuba gear just to get some afternoon exercise. _Maybe Sherlock could join me_? John doubts it, but there's no harm in asking.

"We might not have that long a weather window, so he'd better appear soon," Anderson continues complaining as he tests the colour balance on his camera once again.

"Do you reckon you might go back down to the Bainbridge?" Greg asks John.

"I think Sherlock's seen enough to assess whether it's worth further study. I don't know what he has planned for us next."

"All you need to do is ask, John," comments a dry baritone from the starboard side corridor. Sherlock appears, wearing a different suit to the one in which John had seen him on that first night. This one is black — not a very practical choice for a hot, tropical climate — and comes with a button-strainingly tight, emerald green shirt.

Anderson steps in to clip an inconspicuous microphone to his lapel. Sherlock allows this but glares as he examines the contraption after sitting down on the barstool. "I assumed your camera's microphone would suffice."

"It'll pick up some of the wind even with the furry rabbit, and I want to make sure we capture your voice," Greg explains. "We really should get more of you on tape; you could be the Clive Oppenheimer of marine archaeology?"

Sherlock looks like he wants to be whoever that is even less than he wants to be tar-and-feathered. "I have no idea who that is."

" _Clive Oppenheimer_ , for fuck's sake!" Greg enthuses. "The guy Werner Herzog found for that bestseller volcano documentary of his, _Encounters At The End of The World_? Herzog thought he was just going to film a bunch of stuff about volcanoes, but Oppenheimer was so great it became largely about him, and there's now a sequel, too, and BBC's got him on some science radio shows as well. They'd pay you handsomely for that voice, I'll bet. And you're got even better hair than Clive."

The tips of Sherlock's ears get a bit red, and John can't tell whether it's from anger, embarrassment or both.

"I'm doing this because I have to, not because I have a desire to become some sort of a publicity-hungry performing monkey to simplify science for the ignorant masses."

Greg crosses his arms. "Do you have any idea how much funding is being raked Oppenheimer's way because of those documentaries? Women are sending 'im their _knickers_."

Sherlock rolls his eyes as he straightens his back. "Let's just get this over with." His eyes narrow as he fixes his eyes on the camera. "What are you still doing here?" he asks, appearing to have noticed John only now.

"Moral support."

"And we're rolling," Anderson announces, obviously having grown tired of waiting.

"Professor Holmes–" Greg starts, "Could you tell us about your dive yesterday?"

"Be specific."

"Just… could you walk us through it?"

"John Watson and I descended to a depth of sixty-three metres, at which we came into contact with the wreck of the USS Bainbridge. Our initial survey revealed that the ship had been hit by an explosive, likely a sea mine which had been carried in from afar by currents since this area does not appear ever to have been involved in a military conflict. We entered the wreck through the forward engine room––"

"Um––" Greg interrupts him, "you're not giving a report to a superior officer. Just… relax and tell us what you found."

Sherlock digs out a notebook from his pocket. "I've listed all the artefacts I identified––"

John pipes in. "What were the Wickes-class ships used for?"

Sherlock's head snap towards his direction. "I already told you."

John nods toward the camera. "You told me, yes, but our viewers are curious about that, too."

"Right, yes, true," Sherlock says, and primly rearranges his hands on his lap.

 _He seems distracted_ , John thinks. _Distracted and nervous._

"You'll need to excuse me for a moment. I need to–– There's something I forgot," Sherlock suddenly stammers and drops to his feet.

"What _now_?" Anderson exclaims, clearly annoyed as they watch the man march down the deck. "Was that it, then? A fat lot of good that was," he scoffs.

"He'll be back. I think," John suggests. _Maybe he's gone to shrug off that jacket; he must be boiling in that suit in this weather._ Sweat had already been shining on his forehead.

Sherlock does return ten minutes later and appears a bit more collected. He climbs back onto the chair, smooths the creases on his trousers with his palms and then defiantly juts up his chin and looks at the camera. "I believe you asked about Wickes-class destroyers?"

"Well, John did, but that's as good a place to start as any," Greg replies.

"The Wickes-class destroyers were built by the US navy between 1917 and 1919. Only a few were completed in time to serve in the first world war, and most of the other ones were converted to other uses eventually, making a Wickes-type ship that actually served in combat a rarity. They were designed as a counter-measure to torpedo boats, especially towards the self-propelled Whitehead-type torpedoes. These destroyers were needed as safety escorts for larger warships; Wickes ships were more dispensable. The design was driven by a need for high speed and mass production, and the result is a genuine show of ingenuity evident in the blueprints."

Sherlock then does on to explain some of their technical specs, and there is some back-and-forth between him and Greg as the producer tries to get him to give some context for the data. "The viewers won't know what, say, an _average_ destroyer ship would be like."

"There is no _average_ destroyer; what would be common design characteristics for a warship type depend on what function that ship is needed to fulfil."

Greg seems at a loss of where to go from here about the Bainbridge. "John, I think I'll want you on screen for a bit, too, talking about your dive yesterday."

"I can convey the key points just as well as him," Sherlock protests. "I find that divers tend to romanticise their exploits at the expense of objectivity."

"Maybe a bit of romance is what our readers would enjoy," Greg jokes, and gives John a wink.

"I don't believe that prosaic nonsense is required for the popularisation of science," Sherlock scoffs. "Science reporting should be data-centric, not childish, stereotypical stories about the people involved."

"You don't think it's good to portray the passion with which the people involved treat their jobs? I actually heard that's exactly how Oxford got the Hilti Foundation involved. Some bigshot saw your presentation––"

"I'm not going to discuss that," Sherlock snaps, and his eyes flash with sudden rage. He plants his palm on the wooden railing behind the barstool, obviously preparing to climb down and abandon the interview.

"Why do you speak BSL?" John cuts in.

Sherlock turns to stare at him, movements frozen just as his shoe was about to touch the deck. "Excuse me?"

"You speak twenty-three languages, one of them BSL. Is it for diving? Didn't you know it was unlikely that any diving partner you found would also know it?"

Sherlock's expression turns apprehensive. "Are you still recording?"

Anderson looks hopeful. "Yes?"

Greg looks encouraging; he nods, even waves his hand in a circle to prompt Sherlock to answer.

"My mother died of cancer when I was six years old." He bites his lip, unsure whether he wants to go on.

To John, he looks unemotional; perhaps his hesitation is connected mostly to the idea that he doesn't want this documentary to be about him — just about the archaeology in this area.

"The chemotherapy available in those days for what I later learned was aggressive osteosarcoma was highly toxic to the inner ear. She lost her hearing. Learning BSL allowed us to communicate."

"Did your whole family learn it?" Greg asks.

"No, my father… couldn't spare the time, I suppose. He was a commanding officer at the naval base at Portsmouth where we resided at the time. My brother had been sent to boarding school."

"I'm sorry," John says. He shouldn't talk since it will get caught on tape, but the atmosphere has become tense, and it just needs to be said. "Do you remember her well?"

"No, I… it's strange," Sherlock says, averting his eyes from the camera. "I don't remember much about that week except for one thing. The Mary Rose. My father wasn't home much in those days, but a day after the funeral he took me to see the wreck being raised from the seabed."

Greg gives him a moment; John suspects he hopes that Sherlock might continue if he's not disturbed.

"I had never quite realised what things lie down there, how many submerged human remains and shipwrecks and sunken cities there are. The sea has been livelihood, the topic of cultural works, a home, a profession, a stage of great tragedies and battles. Biologists are even certain we all came from the sea but shed our ability to live there somewhere along the way. After I saw that ship rising from the sea, I read everything I could get my hands on about such things. I told my father I wanted to be a pirate. He told me it was a bad idea because the navy always captures them." A slight smile threatens to erupt on his features, but he forces it away. "' _The light of past discovery draws me forward. Its shining light guides me to the glory of exploration_.'"

"Columbus?" Anderson suggests.

"Of course not," Sherlock replies. "Had it been Columbus, I would have _naturally_ quoted him in _Italian_. That was Sir Francis Drake."

"Whose ship you hope to find," Greg suggests.

"I recognise that in these waters, hoping to find his unaccounted-for caravel is akin to hoping one might come upon the proverbial needle in the haystack," Sherlock sighs, "but if scientific pipe dreams and inconsequential childhood stories are what you want in this documentary, that should have satisfied your needs."

"So, you wouldn't mind if we put all that in? It was great," Greg replies.

Sherlock's expression is strange. "It appears this conversation is a reminder that sometimes one must give things of oneself to further the progress of science."

"I mean, that was personal," Greg explains. "You made it clear you don't want this documentary to feature you very heavily, but…"

Sherlock gives him a glare. "First, you push me to talk about myself, and now you want to backtrack; just make up your mind and stop wasting my time. Use it if you must; my opinion is of no consequence, as I have no intention of ever viewing the programme. Do you have other questions?"

The spell of Sherlock's story has broken with the argument, and John feels an urge to leave the scene. "I should go make sure all the dive gear is secure. I think the wind's picking up."

Sherlock is picking at a cuticle. He looks withdrawn, uninterested in his company and the camera. "Stay," he mutters.

John is on his feet. "What?"

"Your questions are significantly more intelligent than Lestrade's."

_Even if they're personal?_

John drops down into the deck chair. Greg is looking at him expectantly, and suddenly John remembers a conversation he'd had earlier on this trip about Sherlock's diving training. "Um… One thing you'd be much better at explaining than me is why it's a good idea for archaeologists to dive to submerged sites instead of just raising the artefacts up."

Sherlock looks relieved and launches into a rapid-fire mini-lecture on the topic.

John listens to it with half an ear while trying to work out why Sherlock would continue an interview he had originally wanted to avoid like the plague. Was it Greg's point about funding, or does he like the limelight despite looking squirmy under the scrutiny? It's obvious he's a great public speaker and lovely to listen to when he lets his enthusiasm and passion shine through. Why is it so carefully hidden, and why does Andrew think that he was different before?

Before _what?_

______________   
  
  


After lunch, those living aboard the Salaminia watch the tropical storm they have been expecting slide in from the open ocean. It shrouds the volcano on Isla Fuego in grey, whips the palms on the shore so hard that branches are hurtled into the sea. There is an astonishingly clear border to the rain front that lingers by the islands, not yet quite reaching where they are moored in the shelter of the smaller island.

"The altitude of the volcano suspend the clouds," Joseph had remarked as he collected his books and papers from the dinette to keep them from getting wet. Though the rain has not quite touched them yet, the air hangs heavy with humidity.

John, having spent the better part of an hour on the dive deck rearranging things with Dionisio, feels itchy and sweaty, his clothes clinging uncomfortably to his skin. There's little use in changing them as long as he's not staying inside his air-conditioned cabin. Humidity is rising as the barometer plummets.

Sherlock had disappeared from lunch mere minutes after arriving in the dining area, leaving his plate of vegetable pasta untouched. During his brief appearance, he had tugged at his clothes, grunting and glowering in frustration, clearly in a stroppy mood.

Everyone seems on edge — as though the thunder cracking over the volcano is electrifying the very air. The storm hums in their bones, tenses their shoulders.

John wanders aimlessly around the decks — there will be no diving this afternoon. He restlessly drums the safety railings lining the decks with his palms as he walks, unable to settle. He remembers what Sherlock had said about the boat feeling crowded; even though he is currently without company, John can imagine sensing everyone else moving about the narrow spaces. The sea is the only escape, and it's currently a no-go. _Diving with metallic gear during a thunderstorm — a bit not good._ Jose-Perry has been on the radio with the mainland about the weather and has been doing some preparations with the crew; lightning can ruin antennas, fry electronics — including navigation systems. He had mentioned that there is, at least, a grounding rod installed which should offer some protection.

After some more aimless wandering and watching the clouds gathering on the horizon, John takes himself to his cabin. Even the freshly changed sheets feel clammy against his warm, salty limbs as he spreads himself across the bed. There's a band of pressure around his forehead, not pain but tension.

Without really making a conscious decision, he slides his fingers into his pants, gives his foreskin a tentative, languid tug upwards so that it slips over his glans fully. He needs a release, needs… something to be able to relax. Something else than flitting about like a restless sea ghost.

He begins flicking his thumb gently across the exquisitely sensitive fraenulum on every downstroke. He varies the speed, varies the squeeze and the stretch. His breathing speeds up. He can't decide if he wants to prolong it, relish it, or chase a quick, explosive climax. With a determined grunt, he kicks off his pants and shorts, cradles his balls firmly with his free hand while continuing a brisk stroke up his cock shaft with the other.

 _This won't take long today._ He's not had sex for weeks, now — a much longer dry spell than usual. Oddly enough, he'd not taken himself in hand, either. The background stress of being cooped up with plenty of people on a boat, combined with his duties and travelling into the unknown must have distracted him until now. The storm has brought everything to a standstill.

Not having a mind to pleasure himself doesn't sound like him; his libido has always been a well-oiled machine, reliable and regular even on trips like this. He'd had a routine,one where his hands took turns with the hands and mouths and the tight, blissful heat of others as he sunk in and stopped thinking.

_At what point does quantity begin diluting quality?_

Sherlock slips into his thoughts as he begins stroking in earnest. Does he ever just go for it with someone he met five minutes ago? What would it take, what kind of a person could entice him to seize that opportunity? _Nobody would say no to Professor Holmes, would they? Just_ look _at the guy._ God, John would have had him that night at the hotel. A younger John would have jerked off to just a picture of him in a National Geographic article. He likes to think of himself as a man of varied tastes, but something about that very-much-not-subtle convergence of sharp facial features, superiority complex, plush arse, curls that are begging for a good tug and that voice that should be classified as a weapon of mass destruction––

Rain begins pelting the boat just in time to drown out John's gasps as he comes.

Loose-limbed and jelly-boned, he has no desire to crawl off the bed afterwards to clean himself up. On diving trips, moments of smelling and feeling fresh are few and far between as he is often doused in petrol fumes, the smell of human-marinated neoprene, sweat, seawater and the other gunks and funks of living on a boat.

He does grab a tissue to give himself a cursory wipe and as he does, a pang of guilt the likes of which he has never felt suddenly hits.

_Fantasies never hurt anybody, do they?_

Of course not. Yet, John can't help wondering what Sherlock would think if he knew the way John had just thought of him, the things he'd fantasised doing to the man. Things he, judging by what he'd explained, would not welcome. _Was it just that I'm his type? Or was I too aggressive about it that first night? Maybe he wants to be wined and dined and worshipped and courted slowly._

Would Sherlock be flattered or put off if he knew that he had just granted John a spectacular release?

  
______________

At four in the afternoon, the skies are dark, and thunder cracks above them. John had fallen asleep in his cabin — the first long nap he's been able to take since they had taken off from port. He wakes up with his hair sticking up and a stale taste in his mouth and a mild headache which can probably be cured with a strong cup of coffee.

 _We probably needed this day for rest and recuperation and didn't quite realise it_ , he decides while taking a piss and using some mouthwash he'd bought a small bottle of at the airport. He always carries one to ensure kissing him is a tolerable experience.

He is ecstatic to find a canned, cold-brewed coffee drink in the back of the upstairs bar fridge.

Anderson is in the bar salon too, cleaning a lens. "Those are Morten's I think, but he's been offering them around. I'm sure he won't mind if you grab one."

"Have you taken a look at our GoPro footage? Can you do something with it? Greg seems to think so."

"We can use some software filters to clean it up, and the resistance of water to movement eliminates a lot of the shakiness that plagues handheld on land. The visibility was good and the resolution up to the BBC standards so yes, I think we can do a lot with that footage. With some skilful editing, it can be quite an exciting section. The silt-out looks quite dramatic."

John nearly shudders at the thought. He's experienced the phenomenon countless times, but rarely in connection to being effectively trapped in a disintegrating steel bucket at sixty metres down. Knowing that there's a way out and a safety line between his fingers sure helps ward off panic. _Sherlock did great, though_. John has to admit that his partner's calmness had helped him keep a level head, too, and that's exactly how it's supposed to work. Thinking that he's immune to panic and confusion and disorientation just because he's very experienced would be a recipe for disaster.

He looks forward to doing more dives with Sherlock. Whatever had bothered him on that first dive seems to have dissipated even if he sometimes acts a bit odd and moody on board. _Maybe it was just about having to deal with new people on a dive he didn't help plan._

He leaves Anderson to his gear maintenance and walks up the steps to the top deck. It's mostly covered by a sunshade tarp, so if he grabs one of the bean bags in the middle, maybe he can watch the storm without the rain reaching him.

He pauses just after letting go of the staircase railing: Sherlock is sitting in one of the small wicker sofas on the opposite side of the deck, smoking.

John wonders how the hell he'd kept that habit from the rest of the group for so long. _Then again, Sherlock seems to keep a lot of secrets._ The man's shoulders are hunched, and John senses that he doesn't want company. He's wearing long-sleeved T-shirt just like John since the storm has brought in cooler air from the ocean; John realises Sherlock always wears something with sleeves, even when it's very hot. _Maybe he thinks regular T-shirts are for the idiot masses._

He doesn't seem to have noticed John, who stands watching as he grinds down his cigarette butt into a coffee mug, then lights another with a swift, rehearsed flick of a lighter. He then sneezes suddenly, grabbing a paper napkin which had been kept from blowing away by the mug on top of it.

 _I hope he's not getting a head cold_ , John thinks.

There are some papers on the small, glass-covered wicker table in front of Sherlock. He learns forward, taps the tip of the pen he picks up in a line down the page as though counting something. He jots down a few things, then draws a line and adds something beneath. With a shake of his head, he then slumps back against the cushioned back of the sofa and takes a long drag from his cigarette.

After wondering whether an interruption might be welcome, after all, John decides to retrace his steps quietly back down to the upper deck. _He probably came up here so that he wouldn't be disturbed._ It appears that Sherlock can't push whatever worries him to the back of his mind even on a rest day.

  
  


**Notes for the Chapter:**

> [Clive Oppenheimer is _real_](https://en.wikipedia.org/wiki/Clive_Oppenheimer), and he is all the awesome. I strongly urge you all to watch the Werner Herzog documentaries he's in because he is great and so are the films. He's the [professor of volcano things at Cambridge](https://www.geog.cam.ac.uk/people/oppenheimer/). He's been described as Herzog's [volcano Virgil](https://www.guernicamag.com/clive-oppenheimer-werner-herzogs-true-virgil/) and how could anyone resist his adorable self like seriously.
> 
> And before we get completely carried away by all that hot smokin' lava, here are [some pics to help you visualise the boat](https://jbaillier.tumblr.com/post/190461971360/j-i-love-all-the-extras-you-put-with-your-fics#notes) our #idiotsnowinwetsuits are on.


	9. Out of Their Depth

It takes two days for the visibility to improve. The water clears of things stirred up by currents faster on the ocean side of the island group; in the shelter of the middle lagoon, things are still mucky and currents unpredictable on the second morning after the storm, so the team decides to pick a deeper, larger wreck to explore. The one that Sherlock declares to be of most interest rests at the bottom of the deep, straight between Isla Fuego and Isla Santa Maria Madre.

What sits at the bottom there has not even been glimpsed by army divers; they had not possessed the equipment or the training to descend to what Dionisio has measured to be ninety-six metres below the surface. What has wrecked here is known only from written records.

"The _Ormancey_ ," Sherlock declares and dramatically unrolls a large piece of parchment onto the mid deck salon table. "Named after a French general in the Napoleonic Wars who commanded troops in the Battle of Caldiero, it is a French pre-dreadnought battleship from the 1890s. The Guatemalan army purchased it from the French in 1910. A young republic, they couldn't afford to build their own fleet, so buying older battleships from Europe seemed like a lucrative deal. However, during practice manoeuvres in particularly difficult currents, brought on by a storm which I suspect was not dissimilar to the one we weathered, it sank in the straight between the islands. All but two of the seventy crewmembers were rescued. Not many French battleships of that era have survived in such an original form; major alterations were done on many prior to the first world war. Not a single one remains unscuttled or disassembled — except for the Ormancey. The _Masséna_ , for instance, was reduced to a hulk and scuttled as a breakwater off Gallipoli in 1915. Such a waste," Sherlock laments resignedly and begins running his fingertip on the schematic as he explains about its general design and measurements. A hundred metres long, it's a swimming fortress of massive magnitude for its age.

John is surprised to learn that its main armaments were just two cannons.

"They each had a range of two hundred and fifty degrees, which means they could protect the ship very well. Agility over bulk," Sherlock reasons.

John has to admit that the schematics of the boat in Sherlock's papers look impressive; there aren't that many warship wrecks of this calibre available for diving, and it appears unlikely that anyone has entered this French warship since it sank.

"The _Masséna_ significantly exceeded its design weight and suffered from stability problems; they could barely use the cannons to full effect. Relatively little documentation of the _Ormancey_ remains apart from these schematics; it will be fascinating to try to discern whether it had the same problems its sister ship suffered from."

A meticulous dive plan is made. John and Sherlock will be the only ones descending; the rest of the team will provide support, act as a contingency in case a rescue diver is needed. Morten and Anderson would be the two other divers qualified for the depth, but John had examined the cameraman's ear and found that fluid was accumulating in the inner ear, a sign of a smouldering infection. There is no question about it: John cannot clear him for such a deep dive. They'll be going down to such a depth that the limits of Sherlock's training and experience will be felt acutely, and John doesn't want to have Anderson's eustachian tubes to worry about down there. They need Morten to stay on the boat in case he needs to provide rescue diver services. Dionisio had bowed out, too — Greg had challenged him to a tequila shot competition the night before. John had some select words about that.

"I could have used him on this one, Greg, for fuck's sake."

"Poor bloke's not had a day off since we departed," Greg had protested.

John had then sprung the news about Anderson's ear, which had wiped the smile right off Lestrade's face.

"This entire bloody film's gonna be shot on a GoPro at this rate." Grumbling, he'd disappeared down the stairs, presumably to find coffee to fix his own rather obvious hangover.

It'll be just the two of them, then — him and Sherlock — and John is fine with that even if feels the pressure of being the more experienced diver quite acutely because of it. Even though Sherlock is qualified for this dive, John is the senior both in training and experience and will be responsible to some extent for how this goes. Even when using trimix, they are both likely to get slight nitrogen narcosis, and they need to decide on several potential turnaround points for the dive plan, which will help with decision-making. A diver may abort a diver at any stage for any reason but doing so on a deep tec dive is complicated: the divers can't just ascend to the surface; they are facing over an hour of decompression stops even if they pull the plug soon after reaching their target depth. Any problem that arises needs to be solved at depth; there is no quick bailout that wouldn't lead to likely lethal decompression sickness.

Had John not witnessed his partner's calm and rational behaviour in the Bainbridge, he would have re-paired himself with Morten and demanded that Sherlock sit this one out. Not all of John's worries from that first dive have disappeared, but he keeps reminding himself that anyone can have a shit dive, a bad day, or a sudden wobble. There's also the fact that Sherlock is the expert on these wrecks; even armed with video cameras, divers without his knowledge base would not know what to look for in terms of using their limited bottom time for fact-finding.

Armed with a good plan — one that includes plenty of — wide safety margins, they should be able to do this safely. Well, as safely as one ever could penetrate a slowly disintegrating hunk of metal on the sea bottom at nearly a hundred metres deep.

________________

An hour later, John walks past Sherlock's cabin door, which has been left ajar. He peeks in through the crack and spots his partner struggling to get his wetsuit on. Trying to slide damp neoprene — the air is so humid that their wetsuits haven't dried properly — over sweaty skin is always a sporting event.

"Have you got lube?" John asks off-handedly. "Makes that a lot easier." Sherlock probably knows this, and every bloke John knows in the industry carries a tube for… various reasons.

"Shut that damned door!" Sherlock snaps.

John does as he's told. He's tempted to ask one more time whether Sherlock might be willing to reconsider using the radio-capable full-face mask but elects not to since it's not a good idea to introduce new gear for the kind of dive they have planned even if having the best communication system possible would be good for their unbalanced experience profiles. On the other hand, even if using it doesn't require any additional practice, John has a hunch that adjusting to anything new might be a struggle for someone as meticulous and particular about things as Sherlock. He doesn't want to shake the man's emotional balance and routines in any way before a deep tec dive. "See you on the dive deck in fifteen?" He calls through the closed door.

There's a non-committal grunt from inside the cabin; perhaps Sherlock is still struggling with the wetsuit.

John drops off his T-shirt and shorts in his own cabin on the lower deck and then walks to the dive gear area in just his black Speedo. After pulling on his own wetsuit, he dons his Mares Trilastic boots. Sherlock walks in at that moment, barefoot and zipped into his custom suit. He's wearing an aloof, concentrated expression that discourages even a friendly greeting.

They recheck that all the parts of their isolation manifolds, wing frames and regulator sets are functioning and intact. John has a laminated checklist he goes through every time before a tech dive; he'd shown it to Sherlock before their first joint dive. Sherlock had told him he has a similar one but did not produce it for John to have a look at.

"Where is it?" John had asked, and the answer had been Sherlock pointing a finger at his own head. "All in here."

Sherlock tucks a writing slate into a pocket. "I told you; I don't want idiots breaking my concentration with inane chatter. That includes you."

"I didn't even say anyth––" John starts to protest. _God, he's in a cranky mood._

"You oscillated outside my cabin door. It was not much of a deductive leap to realise that's what you were thinking about since you elected not to address the issue. More divers should learn sign language," Sherlock adds in a superior tone.

There is one sign John has already learned from the man—one he's seen Sherlock use underwater several times about other divers. It clearly means 'idiot': a fist to the temple, then explosive gesture outwards.

John focuses on his checklist again.

John runs through the final items in his head: _Two torches. Tanks. Computer. Mask. Fins with two spare straps. Writing slate. Spare computer. Radio connection to surface checked_.

Sherlock looks to be doing the same, having arranged all the aforementioned gear save for the radio on the back deck. Just as before, they will enter the water with just two of their six tanks and receive the rest and clip them on while floating on the surface. Having so much equipment can, of course, make it challenging to explore narrow spaces such as caves and wrecks, but they're also a safety blanket, a lucky charm, concrete evidence of life insurance in an environment where inhaling even one lungful without a regulator would lead to death. It is not set in stone yet whether they will penetrate this wreck; they will see how long an external examination of it will take, and then look at their gas reserves. There's no way to know what sort of condition the wreck is in and whether there was a convenient entry point created when it sank, or if they'll have to make their way in through entrances the crew had used.

"Fuck," Sherlock curses from the opposite side of the bench. He's dropped an isolation manifold valve screw which has rolled underneath his twin trimix tanks. John helps him lift them — already connected to two nitrox tanks, the configuration is bulky. He then watches Sherlock fumbling with the screw as he tries to get the valve secured. His fingers slip and shake a bit, but he gets the job done. He's blinking hard; John reasons it's probably because of the spray from the waves which are beating the side of the boat flinging droplets into his eyes.

"I forgot––" Sherlock suddenly says, and jogs back up the stairs.

When he returns a few minutes later, John can't work out what he had left behind since he returns empty-handed. "Left the kettle on?" he jokes.

"Excuse me?"

"Never mind."

Sherlock slips into his wing plate BCD and clips on two small nitrox tanks and an oxygen tank. This much they can manage to jump in with. John sits down for a moment to watch him fasten the straps; his hands seem steadier and his movements less jerky, now. _Nerves?_ Focusing on the tasks at hand always helps John with his jittery nerves, so the same is probably true for his partner.

"Sherlock?"

He gets a hum as Sherlock programs his dive computer with the appropriate depth alarms and updates the info on their trimix and nitrox percentages.

"Sherlock, can you stop for a moment?"

"Yes?" Pale eyes meet his.

"Everything alright? You seemed a bit on edge earlier."

"I'm fine, John."

"Anything worrying you about the dive?"

"Dionisio couldn't give us much of a current estimate, but we should be sheltered from the worst strait currents at this spot."

 _Do I confront him or let him hide behind that?_ John decides that what they're doing is too risky to let things slide. "That's not what I meant. That's a general risk considered in our plan. How do you feel about this dive?"

Sherlock pulls on a neoprene glove. "I can't _feel_ anything about it before it's started, can I?"

"I just need to hear you're not too nervous or worried or…"

"Or what?"

Sherlock is now just standing in front of him, leaning on a support beam so the waves knocking the boat about won't tip him over. He's biting his lip, avoiding John's gaze.

"We both have to feel fine about this. Any diver can abort any dive at any time. No shame in saying you don't want to do something. If you're nervous now, going down won't help."

"Why would I be nervous?"

John wants to punch something. He would never have expected openness and honesty from the man, but this is a matter of life and death. He needs to hear the words, and he needs to _believe them_. "Are you alright to do this dive with me today, with this gear, to this depth?"

Sherlock clasps his hands behind his back underneath the metal frame of the wing plate, and tips his chin up, meeting John's gaze. There is defiance there. He even manages a tight smile that doesn't quite reach his eyes. "I'm perfectly fine with our plan, John."

"Good. Because I have that same right to abort at any time, don't I, and you'll respect it?"

"Why are you lecturing me about basic etiquette?"

"It's not really etiquette; it's safety."

"If you decide to pull the plug, so be it. I don't know what's got you in such a tizzy," Sherlock says, and his tone is now leisurely, even a little bit teasing. "I knew diving experts were sticklers for rules, but you are taking some aspects of it to a strange extreme."

John shrugs. "It's kept me alive so far.”

  
______________  
  
  


Bobbing on the surface, John feels like a cork since he's had to inflate his BCD bladder rather full to keep all his heavy gear afloat. He fins himself away from the boat and turns to face the vessel and Sherlock, who's clearing his mask right next to John. A larger-than-average wave sloshes over them and causes Sherlock to cough since he hadn't had his regulator in. Since they're so close, John notices his breath smells like bananas. _Is that what he had for breakfast instead of joining the rest for pancakes? He must have eaten it just before we kitted up and jumped in._ Having a light snack before a long dive is a good idea and reassures John about Sherlock's mindset for this dive. _If he planned even his meals around this, he can't be too distracted._ John recognises his tendency to micromanage and be overbearing about less experienced diving partners; there's a fine line between motherhenning and being exceptionally meticulous about safety. _I trust him down below, so I have to trust him on the surface. Sherlock is the best judge of whether Sherlock is fine, not me_.

He waits until Sherlock is done with his gear. Then, after a mutual nod, both men put their regulators in their mouths, lift the vent hoses of their wing bladder above their heads, and press the vent buttons so that they can begin descending.

They'll dive on air until they reach minus thirty metres. There, they will change to trimix. If they want to change from one trimix tank to another, they can simply open and close valves on the isolation manifold without changing the regulator. Swapping between gases is a bit more complicated: they will have to close the trimix tanks, then replace the regulator system connected to them with one connected to the right alternate gas. Removing a regulator from one's mouth and replacing it with another may sound complicated, but it's a skill taught on the scuba diving beginner courses; anyone might need to borrow gas through another diver's secondary regulator if something happens to their own supply. It's an elementary skill for any diver but can be a stressful moment all the same.

The anchor line of the boat has been carefully placed just upstream of where the ship has been recorded to have gone down; following the line will lead them to the front of the sunken ship and prevent them from having to waste time and energy kicking against the currents. Especially in a strait, there might be some currents washing the sides of the wreck even at great depth.

They're now both a few metres down and swap OK signs—thumb tip and forefinger tip connected while the other fingers are stuck up. John then tests the radio.

"Greg? You hearing me? Over."

"Loud and clear, over." Lestrade's voice rattles through the system. John wonders how good the connection will be at the depth of the wreck.

Sherlock is hovering at a stationary depth, making sure all his gear is still tucked neatly into his pockets. When he looks up and notices John watching him, he gives the OK sign without delay.

Having established that their descent is going as planned, John empties his lungs and let himself begin sinking again. He can finally relax a bit and look down towards the blue depths. He can't resist the urge to close his eyes momentarily to enjoy the sense of weightlessness. Without a visual reference, it's hard even to tell he's sinking without glancing at his gauges. The only sign that depth is increasing is the need to keep equalising his ears and sinuses. His bulky gear no longer bothers him: it's just as weightless as him. Tanks which had required some lifting and grunting on the boat can now be shifted around with a finger. They have both placed tanks under their arms to make their form narrower; they can be reorganised if they decide not to penetrate, after all.

John can't help humming a little. A small shoal of barracudas just minding their own business floats by calmly.

"Considering a third career in musicals?" Greg chuckles through the radio. "Wouldn't quit your steady day job just yet. Over."

"I don't have a steady day job, that's the whole point," John remarks. "Over."

At twenty-nine metres, his dive computer chirps the first warning: it'll soon be time to swap to trimix. Since the current had been nearly non-existent on the way down they hadn't been holding on to the shot line, but now, for convenience, they both sling an arm over the rope as they open each other's trimix tank valves, change to the connected regulators and pack away the air tank gear. John gives his partner a grin and gets a reserved but unhesitant smile in reply. He gives Sherlock's neoprene-clad arm a pat before pushing himself off the rope. He prefers to descend without holding on to one. _Why waste a good freefall?_ For him, the greatest amount of stress regarding a specific dive always happens on the surface before the dive starts. Once in the water, training and experience and instinct take over. Only that moment exists. This is him in his element, doing what he was _born_ to do.

Sherlock steeples his fingers below his chin as he sinks slowly towards the depths, John following close by. _Maybe he sometimes enjoys this just like I do, and just won't admit it,_ he muses as he watches his partner descending.

At seventy metres, light is becoming scarce, but the visibility is superb, so even from such a height, John can now make out the faint outline of a ghost of a ship looming darkly on the sea bottom. Not many people would describe the sight of a slowly decaying, submerged warship as beautiful, but to John, it is precisely that: a treasure trove of history and diving challenge — a place only the skilled and the privileged can visit. His heart is thudding against his ribcage, a good sort of adrenaline making his blood sing; he reminds himself not to let his breathing rate increase. He loosely grips their shot line, repositions himself so that he's descending belly-first so he can keep an eye on both their target and Sherlock. This position slows him down conveniently; no need to add much air to his wing bladder yet.

It's hard to make sense of Sherlock's expression due to the mask and the regulator, but he appears calm. _Why shouldn't he be? So far, so good._ There is no safe stage to any tec dive — accidents and problems can happen at any point, but John's worries about his partner's nerves have mostly disappeared, now. _Maybe he's like me and gets his fretting out of the way on the boat._

As they continue their descent, the outline of the ship becomes clearer. The light dims as depth increases, and at eighty metres, they light their diving torches.

John thinks about the two crew members who had gone down with the ship. Where had they perished? Had they drowned fighting the waves or trapped in the sinking vessel? Human remains are rarely preserved very well in wrecks since the local fish life tends to snack on the flesh. The most they could expect to find are some bones, and the ship is huge, so even that is highly unlikely.

Once they're at the depth of the edge of the top deck, John releases a burst of air into the bladder of his wing: the air he had there is now so compressed that its buoyancy effects have diminished. He watches Sherlock do the same: his movements are purposeful, fluid and fast, and he wastes no time in giving John the OK sign after. He's dug out a larger writing slate and a pencil for making notes.

They make their way to just below the edge of the front deck. Excitement ripples between them as they confirm the ship as the _Ormancey_ ; John makes sure to position himself so that the GoPro he's carrying will get a good view of the mostly coral-covered name.

There's one mast, two top cannons just as Sherlock had explained, and a low-ceilinged pilothouse. There's also a large hole on the side of the front of the wreck — a nice, potential entry point for the penetration. John has dived several gigs where the job was to try to find out what sunk something, but he was always the dive specialist, not the ballistics and explosives expert. When he gets hired to investigate maritime and diving accidents, he tends to get partnered up with such professionals from the local emergency or police services. _Never someone as good as Sherlock, though._

Sherlock is scribbling something on his smaller writing slate, which he shows to John.

DECAY - ROCKS UNDERNEATH CRACKED IT IN HALF, it says. John wonders how he can tell so quickly the difference between a ship breaking up as it goes down, and the results of stress fractures giving in and the ship disintegrating at depth over decades. _Then again, he's the professor, not me_.

John checks his gauges, then his computer. _All good_. He doesn't feel narced, his breathing pattern is calm and economical, and there is little current. When he turns around, he sees Sherlock gliding over a safety railing on the front deck, then jack-knifing his body so that he can look, head-down, at something on the deck. John joins him and finds a colourful shoal of goatfishes guarding a porthole and a large, lazy moray bobbing its head out of it. Perhaps it and the smaller fishes have joined forces in guarding their home. Wrecks, especially ones far offshore, tend to turn into miniature reefs — safe havens for all kinds of underwater creatures. Sharks are also frequent visitors at wrecks since the plentiful fish life offers a snack bar for the apex predators. During the dives in the Graveyard, John had spotted several shortfin mako sharks. A rare, small species of sharks — the white-saddled catshark — inhabits these waters according to their captain, and John has been hoping to see one. _It probably doesn't dwell this deep, though._

Once they've done a swim-around of the entire vessel and Sherlock has nearly filled one side of his slate with notes, he touches John's shoulder and makes a gesture with his hand towards the hole on the side of the wreck. The look in his eyes makes him seem impatient to penetrate. After looking at his gauges, John nods; it's a good idea to do the deepest and most demanding parts of a dive as early as possible when they're not tired yet, and there's plenty of gas left. According to their plan, their options at this point are to stay outside the ship, abort the dive, enter through the larger portholes above the ballast rooms or use whatever better option for an entry point they might find. Sherlock had explained that a French warship of this class wouldn't have corridors — instead, rooms will open directly into other rooms. That should mean less cramped conditions than on the Bainbridge.

They pick the spot where the hull has broken in half as their entry point and fin from the open ocean into the shadow of the overhead environment into what must be the manifold and portable pump station. Sherlock is frowning in concentration as he starts rapidly jotting down notes; the gentle current caressing the ship and extending a bit into the opening makes him float towards the edge of an old, broken, disintegrating electrical cabinet, and his regulator hose snags on a piece of metal strutting out of a wall. Thankfully, by the time he notices something's tugging at his mouth, John has moved in and swiftly released the hose before the metal has a chance to cut into it. John points at the broken cabinet and the rest of the mess of gear and wiring on the wall and uses the diving sign for 'danger' to remind his partner to be more vigilant. His reply is an eye roll.

Instead of heading to the top deck for the C.P.O. quarters, Sherlock heads down a stairwell. John curses as he follows: their plan had stated that they were not to venture down to the lowest deck at all. But, it's hardly the first time that curiosity gets the better of a diver. Thankfully, after two small, dark, empty rooms on a deck which must have been below the waterline, Sherlock seems to get bored and makes his way up a narrow passageway to a higher deck level. The crew's messing and berthing prove to be as interesting as they had been on the Bainbridge: they find plenty of personal items, some of which Sherlock lists on his slate. He instructs John to have a look at two cabins while he inspects three across the hall. Unfortunately, the ones assigned to John turn out to be empty; perhaps the Guatemalan navy had operated the vessel with just a skeleton crew on that fateful night.

After regrouping in the corridor and inspecting one more cabin, John tugs at his Sherlock's fin to get his attention so that they can compare gauge readings. They're in what could well be a recreational area for officers with a large window with the glass still intact. This allows a bit of dim natural light to enter the space, and John can see the bubbles they've exhaled gathered on the ceiling. From below, the air-water interface looks like a mirror.

Their division of labour follows what they had established on the Bainbridge: John is laying string from a reel as they advance; most likely they will exit the ship from somewhere other than where they entered, but he'd never do a penetration this extensive without marking his route. The Bainbridge had been a sobering reminder that it's always a possibility that a diver entering a wreck might have to escape it blindly. To avoid this, they are frog-kicking sideways and being careful not to fin too hard, occasionally using their hands instead to push themselves off safe-looking surfaces.

"John, this is Greg. Over," his radio rattles. Lestrade's voice is metallic, staticky.

John is impressed with how well the radio still functions this deep into the wreck. _Maybe it's the large windows in this room._ "John here. Over."

"How are you guys doing? Over."

"We're fine, can hear you surprisingly well. We're mid-ship, middle level. Can spare another twenty minutes for more exploration, then we'll probably do a flyover of the top before heading for the shot line. Over." John fins over to an opening into a bigger room since that's where Sherlock had just disappeared.

"Getting a bit choppy on the surface; just wanted to give you a heads-up. Over."

"Current nearly non-existent, we can probably use the shot line to get ourselves back on board if need be. Over."

"Good, good. I'll leave you to it. Over."

John makes another routine check of his gauges, aware that radio conversations can distort his sense of time. Using trimix should diminish the risk of getting narced and thus careless and confused, but in these depths, the risk remains. Adherence to routine is a good antidote against problems. His gauge tells him it's time to swap to their second trimix tanks; their first ones are about eighty per cent depleted, and John likes to keep at least a twenty per cent contingency for the switching process, even if it only takes ten seconds at his slowest.

He fins after Sherlock into a large space that is the forward engine room. He's vaguely annoyed that the man hadn't been paying attention to the fact that John wasn't following after him. On the Bainbridge, they had a satisfactory thing going with mutual vigilance — a particularly important safety factor for overheard environments. If one of them gets stuck, and they lose sight of one another, it might deplete precious minutes for the still mobile diver to get back to help his stricken partner, assuming they find them at all.

The room having no windows means that there are only their torches providing light. John swings his beam around the room, trying to locate his partner. He finds Sherlock hovering in the middle of the large space, his arms lax, his torch dangling off his wrist pointed at the silt on the floor.

John touches his shoulder, and he flinches jerkily. John points the light of his torch to the ceiling so that the gestures he makes in front of his chest are lit; pointing it at Sherlock would just blind the man temporarily. He makes an OK sign and sees Sherlock frowning in the dim light. Then, Sherlock seems to remember his own torch and points it upwards in the wrong angle — right into his own face, which makes him squint and grimace.

It takes a moment before he opens his eyes again and pays attention to John, who points back towards where they had come from, then points at his gauge and mimics turning a valve.

Sherlock does nothing. John repeats his gestures, moving his torch in an arc to make sure Sherlock paying attention. He even digs out his own writing slate and jots down TRIMIX #2, which he shows to Sherlock to remind him to switch tanks.

Sherlock frowns and blinks at John. Finally, he hesitantly reaches under his armpit for the smaller tank clipped to his wing plate harness. It's his 100 % oxygen tank, meant to be used close to the surface to make decompression faster. At first, John thinks he's just readjusting its position, but when he starts fumbling for its regulator, John's eyes go wide. Pure instinct takes over as John does a quick fin kick forward so that he can firmly grasp Sherlock's wrist and stop him. If Sherlock swapped the trimix for the oxygen tank, he'd likely convulse and expire — breathing significant amounts of oxygen at this depth turns the normally life-saving gas into a neurotoxin.

Their eyes meet since they are now close, face-to-face, the light from their torches, hanging off their wrists by straps, sweep the walls. Sherlock tries to pull his hand out of John's grip, and John relents after a moment. He tugs his torch off of his wrist and clamps it between his knees so that most of the small chamber remains illuminated. He spreads his arms, palms upward in an aggressive, inquiring gesture. _What the hell, Sherlock?_ He points at the oxygen tank now dangling between Sherlock's side and his arm — just as it should be — and repeats his mimed question.

Sherlock tilts his head inquisitively at John, then cranes his neck to look behind John into the darkness. Is John imagining things, or does he look strangely pale? He isblinking hard, still, and when he reaches above his head to reach the isolation manifold valve, his movements are so jerky that he can barely grip the round piece of metal.

John wastes no time in grabbing him by the shoulder strap and dragging him into the better-lit room they arrived from. There, John opens the valve for him then watches, relieved, as bubbles continue to be blown through and out of Sherlock's regulator just as before. John checks both their gauges and exhales with relief as he sees that their gas management plant is still perfectly in effect.

He's still holding on to Sherlock's wing plate harness, and now, Sherlock gives his chest a shove to get away. John resolutely holds on and grabs the writing slate hanging from a loop in Sherlock's opposite shoulder strap.

YOU OKAY? He writes and raises the plate right in front of the man's face.

Sherlock's eyes narrow, and he looks behind John again. John glances over his own shoulder, wondering if Sherlock had spotted a shark lurking in the dim.

There's nothing there.

John shakes him by the harness to get his attention again, pokes his finger on the text on the slate.

This brings some life into Sherlock, who suddenly shoves him hard again in the chest. John loses his grip and ends up bouncing against a bulkhead. His torch clatters against the metal since it had been hanging from his wrist.

Sherlock is breathing hard, and he reaches out a hand to hold on to the edge of a balustrade. The movement scares away a shoal of small, silvery fishes which parts on either side of him. This seems to alarm Sherlock, whose hand is visibly trembling as he brings it to his regulator as though he is trying to make sure it stays in.

Approaching slowly from the side, John reaches out his hand into Sherlock's visual field to avoid startling him. Sherlock doesn't stop him from lifting up the writing slate again and unclipping it so that he can more easily jot down a longer message.

I NEED TO KNOW WHAT'S GOING ON

He lifts the slate up for Sherlock to see. Sherlock looks at it, then stares at John with glassy eyes. His left-hand fingers have crept onto his neoprene sleeve and are now rubbing at the edge of it as he glances around them as though expecting company.

Possibilities are racing through John's head. _Is he_ _hyperventilating?_ Blood carbon dioxide level dropping too low can cause paranoia, dizziness, muscle spasms and numbness. Sherlock's respiratory rate is heightened, but not _that_ high, is it? And, he'd been breathing nice and calm before. _Doesn't explain what he tried to do with the wrong tank._ Still, hyperventilation is worth ruling out, so John looks at his stopwatch and counts his partner's breaths per half a minute. Sherlock is breathing a bit more frequently than he should, but it shouldn't be enough to bring on problems.

 _Is he_ _narced?_ John waves his finger in a circle around his ear — a standard diving gesture denomination nitrogen narcosis — to ask whether Sherlock thinks that's might be the case. His reply is an angry shake of the head — as though the man is insulted by the very notion that this could be it. A feature of nitrogen narcosis is the denial of symptoms, so Sherlock's answer is hardly a conclusive way in which to rule the theory out. _Being narced makes you relaxed and carefree, not aggressive or paranoid,_ John reminds himself.

With a firm hold on Sherlock's shoulder strap, John checks that the regulator Sherlock has in his mouth is truly connected to the trimix system and nothing else and is satisfied to find that it's the case.

 _I'll try to fix his breathing, rule out the CO2 as the problem._ He positions himself right in front of Sherlock, then fans his palms back and forth in front of his chest to signal that they should try to breathe in sync. Sherlock's response is an incomprehensible, angry gesturing with his hands. _Damn his sign language_ , John thinks and shoves the writing slate into the man's palm.

Sherlock tries to grip the pencil, but it keeps slipping. Finally, he looks up at John, and his head lolls to the side a little.

 _He looks like he's bloody drunk!_ An astonished John thinks. This doesn't fit any commonplace diving-related issues he can dig out from his memory. All he now knows is that he's facing a diver whose judgment and ability to function are severely compromised. They have to abort the dive, _now_!

The first thing they need to do is get out of the wreck. Confined spaces, low light, sharp edges are risks to any diver, and when incapacitated, they could easily prove fatal. John leans to his right past Sherlock to see whether any of the windows in the rec area have lost their glass and are big enough to exit. Thankfully, there is a window in the kitchenette where the glass is gone, and it's plenty big enough to fit through. Large windows in warships can be a rarity, but in galley kitchens, some can often be found.

Sherlock doesn't seem to be understanding at all that John wants them to leave. He's gripping a broken chair, hands shaking hard.

 _Is there something wrong with the trimix in his tank? I triple-checked the contents!_ _Could I have made a blending mistake?_ What if there's too much oxygen in Sherlock's trimix or some impurity John's tank doesn't have? He knows he had been as meticulous with his gas blending as he always is, and they've used and refilled these same tanks for days without any issues. John checks their gauges; all the readings look fine. He realises he needs to breathe from the same tank to check whether the contents are alright. There's a secondary emergency regulator clipped to the front of Sherlock's BCD, and John reaches out for it, only to get his hand pushed away. This alarms John even further;a diver in their right mind would never hinder their partner from taking their secondary reg. Instead, it seems that Sherlock is adamant in trying to keep John from stealing his possessions. John grabs his wrists and rips the reg from its clip; it is both a relief and a fright that Sherlock seems so out of it that he isn't much of a match for John's determination.

A few breaths from Sherlock's tank fills John's lungs with tasteless, odourless trimix that isn't any different from what his own tank had been providing him. He swaps back to his own primary trimix reg and tries to give Sherlock back his spare. He barely manages to grip it, let alone clip it back to its yellow attachment. John does it for him.

He can't leave Sherlock behind in case he decides not to follow, so he practically manhandles him out the window, feeling like he's trying to shove an unruly octopus into a jar. Finally, Sherlock is out in the open water, and John quickly glides through before his partner floats off into the blue or gets any other strange ideas.

John digs out a short loop of paracord which he uses to tie their harnesses together. Sherlock's outstanding buoyancy skills seem to have disappeared, and instead of just clumsiness, there is now obvious ataxia in his movements — they are jerky, happening in stages.

A few times, Sherlock's head snaps to the side as though he'd suddenly caught something strange in his visual field or someone had touched him suddenly on the shoulder.

SHERLOCK PLEASE, John jots down frantically on the writing slate, TALK TO ME

In the marginally better natural light in the open sea, floating close to the side of the ship, John can now spot dilated pupils. _At least it's on both sides._ Just one dilated pupil would mean a localised problem in the brain, such as a bleed. He grabs Sherlock's wrist, pushes up his neoprene sleeve and finds a rapid pulse with what must be occasional extra beats. John slaps his hand on his chest, then squeezes it into a fist to ask if there's chest pain. A jerky shake of Sherlock's head is his reply. He seems to now notice that John has tied the two of them together, and a sudden rage erupts in an attempt to fin-kick John in the stomach. John raises his hands in frantic supplication, and this seems to placate Sherlock, who tries to untie himself from the paracord but with little success.

John suddenly remembers — and activates — his radio. "Greg, I need your help, over!" He must've been slightly narced, too, to have forgot that it existed. Then again, there isn't much anyone on the surface could have done to help get Sherlock out of the wreck.

The connection rattles into life without delay. "John, I'm right here. Are you inside or outside? Over."

"We're out of the wreck, by the cannon. Over."

"We can't follow your bubbles at all anymore; the waves are getting bigger. Over."

"Something's wrong with Sherlock, and I need to work out what. Over."

"You're ascending, then? Over."

"Not sure we can manage that safely right now; can't drag both of us up while trying to wrestle him. I've got to work this out _now_. Over."

If Sherlock decided to suddenly ditch his weights or swap to the wrong tank or kick off into the blue, mid-ascent John would have much more trouble helping him. Here, shielded by the ship's hull from the currents and with a fixed structure to hold on to keep their current depth, this is as good a spot to do some problem-solving as any. _We can spare the gas for a break of a few minutes._ They have plenty of gas and planned bottom time left.

"What do you need? We're all here on the dive deck. Over." Greg sounds alarmed, now, but John knows the man's good in a crisis. He doesn't get overwhelmed, and he'll turn every stone to help a friend in trouble.

Sherlock has turned to face away from John and is trying to pull him towards the mast. John relents a bit but keeps a hand close to the hull so that he can grab onto something if Sherlock tries to force them to ascend too quickly. _It's probably better that he can't hear Greg's end of the radio conversation_. "I need you to go to his cabin and find something, anything that would stick out, anything that would explain what the hell's going on. Over."

"I'll go look, but do you want me to send Morten down? Over."

"Yeah, tell him to kit up. Over."

"You're sure it's not the gas mix? Over."

"No, I checked, but even if it is, not much I could fucking do about that right now, is there? Over."

He hears faint thudding as Greg must be sprinting up the stairs to the right cabin. "Can you give me any hints about what I'm looking for? Over."

"If I knew what you were looking for, I'd tell you. Over."

They've shifted close to the mast, and John crowds Sherlock between him and the structure, hand gripping the edges of it on both sides of Sherlock. He's not putting up much of a fight anymore, and John really, _really_ doesn't like his colour.

"I'm in his cabin," Greg announces. "I've got nothing out of the ordinary in the sleeping area. Over."

"Don't tell me what you _haven't found!_ " John shouts.

Sherlock's eyes are drifting shut, then snapping open again. He doesn't focus on John or much of anything. His whole form has begun to tremble, and somehow it's different from cold shivers which John has often seen during night dives in particular.

"John, I've got–– He's not listening in, is he? Over."

"No, he's not," John says pointedly. "He's not doing a whole lot of shit right now. Over."

"I've got what looks like needles, John. Thin ones. Orange caps. Over."

"Any meds with those? On the tables, in the toiletry bag, hidden somewhere, just _look, Greg, please!_ Over."

"Shit, forgot there's a fridge and a safe." John hears clattering and cursing; Greg must have tripped over something. "Safe's empty. The fridge's got a box. Two boxes. Three. Over."

"What boxes?! What do they say, Greg?"

"Small one. Pharmacy label says Tresiba, and there are these small glass vials inside. Over."

Tresiba. Not that common a medication, but John racks his brain, and suddenly, everything connects and makes sense. " _Jesus_ _fucking bastard!_ " John screeches into the radio. "He's a _fucking diabetic_!?" John has half a mind to give a good slapping right now to that fucking diabetic, but Sherlock isn't even looking at him. His eyes are unfocused, there's sweat dripping down his face inside the mask, and a quick inspection by John with the help of his torch shows that Sherlock's colour has gone greyishly pale.

"I've got an orange box in the fridge," Greg tells him. "Says GlucaGen. Over."

"Open it!" John orders.

"It's got kind of like… a pen, I guess? A bit like one of those EpiPens, you know? Over."

"Can you see if it's got a glass ampoule inside and not a plastic one? Over."

"Yeah, looks like glass. Ampoule's full, too. Over."

"I need it. Over."

"I'll have it waiting on the dive de––"

"No!" John shouts. "I need it _now_! We've got sixty-five minutes of deco; Sherlock can't wait that long!"

He gives Sherlock a good shake by his shoulder straps, then employs the writing slate again.

HAVE YOU GOT ANY FOOD OR DRINK? John writes. He knows some divers carry energy gel or a drink pouch. With a speciality straw or by squeezing from the pouch, it's possible to ingest things while diving. Most divers rely on just having big enough meals between dives, and insulin-dependent diabetes is usually a contraindication for recreational diving. _Did I see him at breakfast?_ John wonders. He can't remember. At depth, stuff like that often slips his mind. _Right, yes, he skipped the pancakes._ Even when on trimix which decreases the amount of nitrogen exposure, John is hardly at his brightest. Nobody is at their cleverest this many fathoms deep.

 _The banana_ _smell_ , John realises. _He was shaking and angry as a wasp on the dive deck, must have popped up to eat a banana, but the sugar in those is all pretty fast and short-acting._ Whatever glucose had been delivered into his bloodstream by the banana is all gone, now. _Sherlock has gone severely hypoglycemic — it explains every damned symptom I've noticed, and it must have happened on that first dive, too, just milder._

With an alarming delay, Sherlock finally leans forward to squint at the text on the writing slate, then shakes his head.

"I need the pen now, Greg!" John yells into the radio. "Use the ring from the mesh basket, push it down the shot line! Over."

The team has several mesh baskets which can be lowered down to divers for bringing items up. John had devised, years ago, his own model — one with a large metal ring and a largeish weight — which can be slid down a rope without it getting snagged by anything. At depth, lowering something down in free water is difficult because a current could push a long line, even weighted, far away from divers. His shot line solution has never failed.

They just have to _get_ to the shot line — and fast. Then, John needs to fire a glucagon auto-injector pen into Sherlock's thigh through the neoprene leg of his wetsuit. _Thankfully, his custom-made posh whole-body condom is thin enough that it might work._

The writing slate has slipped from Sherlock's grip, and his eyes have drifted shut. John knows he has minutes, at most, before his partner will lose consciousness and probably have a seizure.

The shot line is barely visible in the dim light, but it's there, just in front of the bow. John clutches Sherlock's arm between his own and his side, makes sure their connecting paracord hasn't snagged onto anything in the mast and starts finning towards the shotline. _Thank god there's no current._

Once they've crossed the distance, John hooks his arm around the line. The sea bottom is not visible; the wreck is too tall, and there is too little light. When John glances down, it looks as though they're suspended above an abyss. He unties himself from the paracord and attaches it firmly to the anchor line. He's relieved to find that Sherlock is still conscious and clenching his trembling fingers, shaking his hands from the wrist as though they've gone numb.

It all makes a twisted sort of sense to John, now: all the symptoms truly do fit.

 _H_ _ypoglycaemia_. _At ninety metres deep_. _I'm going to fucking murder him_ , John thinks. _But first, I need to save him._

The radio rattles. "I've got your basket ring thingy, took out the mesh and tied the ring to the orange box. Ready? Over."

"As I'll ever be. Over," John grits his teeth and fixes his gaze upwards to where the surface looms, so far above that he can't see anything but murky blue.

"Morten's descending, and I'm sending the basket down," Greg says. "You're at the shot line? Over."

"Yeah, we're here. Over."

A hand begins to fumble around, presumably trying to grip John's arm. He wraps his own around Sherlock's shoulder, gives it a squeeze. He checks both their gauges — they have to start ascending in five minutes according to their original plan.

Seconds tick on, painfully slow. John is rubbing Sherlock's arm in what he hopes is a reassuring manner, and the man's head has lolled sideways again to rest on John's shoulder. Any attempts to use the writing slate have fallen on deaf ears and unseeing eyes. Sherlock is clearly descending into the stupor preceding unconsciousness.

Finally, John feels an odd vibration in the shot line in the crook of his elbow. Slowed down by the water, the ring with a small object flapping in its wake slides down and comes to a halt and John stretches out a hand to catch it. It's hard to untie the box from the ring since he is holding on to Sherlock with one limb. Getting impatient, he finally tugs himself upwards and catches Sherlock with his knees, effectively straddling the man's waist to liberate his hands and to keep him in position.

Finally, the box is free. John pulls off his gloves and shoves them into a pocket. He undoes the clip on the box, then carefully removes the auto-injector. The rest of the box he lets float down towards the blackness underneath them. He takes great care in pulling off the foil cap from the end of the pen. It's now ready for use. It might be too risky a move to try to jostle their positions around, so he decides that a muscle is a muscle, and grips Sherlock's shoulder hard. He presses the auto-injector against his bicep and presses the button. With a click John feels in his thumb, it releases its contents. Through the wetsuit, John can't know if the needle had been long enough to get sufficiently deep. _Two minutes_ , he decides. _It needs to work in three minutes_. _If it doesn't, we ascend_. Well, _John_ will ascend, towing a dying man. The ascent won't fix the hypo, and to avoid getting fatally bent, they need at least an hour more underwater, preferably longer. An emergency ascent would get them both bent, and they're too far from any hospital for anyone to survive significant decompression sickness _combined_ with a hypo.

John squeezes his eyes shut, wraps both his arms around Sherlock to make sure that they won't lose their connection to the anchor line. He counts seconds, then tens of seconds. A minute. He's too scared, now, to look at his dive computer; if he doesn't know for certain how much time has passed, there's still hope.

When he's at one and a half minutes, he feels Sherlock stirring. It's the only word that would describe the way he gently tries to extricate from John's grip. No longer combative but purposeful.

John snaps his eyes open — and meets a gaze that is no longer glassy and staring but only slightly confounded.

John feels dizzy with relief. _Thank fuck_. Glucagon is a hormone that releases the quick-acting glucose the body stores in the liver instantly. It's a brutally effective first aid, the effects of which won't last forever.

He realises he should have asked Morten to bring down something Sherlock could ingest en route to the surface. "Greg? Where's Morten? Over."

"I am here, ten metres deep," Morten replies. "Over."

"You didn't happen to grab anything to eat with you?"

"I always carry some honey pouches. Are those okay? Over."

"I fucking love you, over."

"John? Over." Morten sounds confused.

"Yes, they're perfect, just get to sixty, and we'll meet you there. Over." There's no need for Morten to descend all the way down to where they are, is there? If the glucagon has worked, Sherlock should be functional enough for them to reach Morten.

 _Okay?_ John mouths to Sherlock. They're so close that Sherlock must be able to see his face well through his whole-face mask.

Sherlock nods with only slight hesitation, readjusts his harness.

John exhales hard, squeezing his left hand into a fist to relieve the tense coiled he had turned into. _He's okay. Relax. Focus._

"We're okay," he tells Greg and Morten on the radio. "Over."

"Repeat, please, over," Morten requests.

"We're okay. We're ascending. See you at sixty, over." John checks both their gauges — Sherlock actually offers him a view of his set. John almost gets a sense of timidness from him, of an odd eagerness to help. "Won't need extra tanks. We're ascending, over."

"Can you use the shot line? Waves kind of nasty, over," Greg says.

"We're coming up the line, yeah. Over."

"Be safe, John. Over."

Things may have improved dramatically, but John knows it won't last long. When the boost to Sherlock's glucagon-starved brain from the glycogen stores is eventually depleted, there is no other failsafe left in his body. They need to get up before all of those stores, and the effects of the honey Morten's got are gone. Sherlock needs a meal, fast, once they're back on the boat.

They make their way up the line to sixty metres without much incident. Sherlock is quiet, withdrawn, a little pale and shaky still, but he manages all the necessary tasks satisfactorily. John checks and double-checks everything he does, demands OK signals every ten metres.

The last ten metres of ascent to where John spots Morten waiting for them feel endless. Usually, John enjoys the ascent, relishes the sense of a job well done. It can be downright meditative, but not today. He's got a patient to look after, and a major bollocking to deliver.

_Who the bleeding hell is the physician who cleared Sherlock for diving? If he gets hypos without recognizing them himself, he's an epic fucking liability!_

John gives Morten's arm a pat and a squeeze when the three of them are united by the shot line. Honey is offered and consumed, and then they continue up the line to a depth at which they can swap to nitrox. Sherlock seems exhausted and allows Morten and John to assist him with even the simplest tasks. At thirty metres, John can finally make out the waves high above; the surface now looks like a churning cauldron. He sincerely hopes Sherlock will be able to manage some of their thankfully short surface swim back to the boat on his own. He's glad for Morten's presence; they can tow Sherlock back to the boat together if need be. This is going to remain a rescue mission as long as they've not yet scrambled onto the dive deck. _Possibly even after._

**Notes for the Chapter:**

> Don't ask me about the realism of certain diving-related details in this chapter. Let's just not get into it. *cackles* Sometimes realism needs to shift a bit to give space for fictional drama. What is accurate, however, are the descriptions of hypo symptoms and glucagon as a quick fix for them. The Masséna is a real ship and a real story; the Ormancey is fictional but modelled after the Masséna. I have no idea what ships the Guatemalan navy possessed in the early 1900s. You probably guessed that the USS Bainbridge was fictional, too.
> 
> Let's have a look at how the pros do it: [a dive to the SS Kreta at –163 metres](https://www.youtube.com/watch?v=xKfo96bMCcg&t=623s). As a bonus: at the start of [this wreck dive video from Malta](https://www.youtube.com/watch?v=vSK4SL7tIYg) there is wonderful footage of a diver enjoying the floaty descent down towards the shape of the wreck looming below. The P29 is one of the only wrecks I have penetrated.


	10. Bed of Nails

**Notes for the Chapter:**

> Remember that trigger warning I mentioned? If you haven't read it yet and you think you should, do it before you read this chapter.

Sherlock's arm firmly clasped between his own and his side, John readjusts his right-hand grip on the shotline to keep them in place. Morten is on Sherlock's left side, currently dumping the weights attached to his BCD down to the ocean bottom to increase his buoyancy once they're on the surface. It's a standard procedure in an emergency, yet one often neglected — many dead divers are found with their weights still attached. However, they should not be dropped at depth, since ditching them underwater can lead to an uncontrolled ascent. That might then result in DCS or even an instant, catastrophic lung injury due to air expanding violently and ripping through lung sack walls.

During their ascent, Sherlock has been withdrawn but willing to communicate whenever he's been asked something. John hasn't physically let go of him even for a second after they had left the wreck behind and has sworn not to loosen his grip until they're ready to climb back onto the boat. He's assisted many injured and ill divers before, but never on such a deep dive and never has the reason for a very-near-disaster been something so patently preventable.

John still has a hard time even trying to wrap his head around the whole thing. _He had no trouble hiding his smoking habit from everyone. No wonder he never let anyone into his cabin. Explains why he'd have Mariza delivering his smaller meals at regular intervals._ There seems to be at least some pertinent self-management going on there, but how could it then turn so dodgy when it came to the diving? He studies Sherlock's face as if his expression could telepathically explain to John how someone so highly intelligent could miss the obvious.

Their eyes meet, but Sherlock quickly averts his gaze. _Embarrassed? You should bloody well be_. John taps on his shoulder to get his attention again, then tilts his head to the right, closes his eyes and presses his palm to his own cheek to ask, _tired?_ It's not a standard diving signal, but no one has ever failed to understand it.

The look Sherlock gives him tells him all he needs to know. Open defeat and exhaustion now reside behind those strangely coloured irises.

 _I'm on to you, now,_ John thinks. _No more hiding_.

Radio chatter has been kept to a minimum and strictly down to business, and while John would have naturally preferred to be able to talk to Sherlock at the wreck, perhaps it's now better that he can't hear what John would voice to him right now. Giving a stricken diver the bollocking of a lifetime before they're even out of the water would be bad form, but in his current mindset, John isn't certain he could resist the urge.

Morten deploys an air-filled buoy to make sure the boat knows they're there. Even though they're hanging on to the shot line, it's always good to signal position in a belt-and-braces manner. John is grateful for Morten's calm presence and skilled assistance; he decides he would be happy to dive with the Swede anywhere and to any depth. Even though John's in charge, Morten is clearly self-directed when it comes to assisting in a rescue and has shown exactly the kind of resolute, skilled initiative John would expect from a tec partner.

The force of the waves can now be felt even though they're still five metres below the surface. This is where they were compelled to halt their ascent to make their final decompression stop in order to safely vent off all the nitrogen that has diluted into their bloodstream. Morten is on nitrox, while Sherlock and John are about to switch to the tanks which had nearly killed Sherlock in the wreck — the 100% oxygen. By displacing nitrogen, it should greatly accelerate their off-gassing. Even though they will have completed all of their planned decompression stops, any injury or illness underwater might increase the risk of DCS, so John had made the decision some twenty metres below to put Sherlock on oxygen on the boat for at least for twelve hours as a precaution. _Precaution and a lesson in how serious things should not be forgotten._

Sherlock manages to unclip the small oxygen tank from his utility belt and attach it to a metal ring on his utility belt. With Morten's help, he manages to guide the right regulator into his mouth and press the purge button to empty it of water before taking his first breath. John keeps an eye on his breathing and notices that it becomes a bit heavier in the next few minutes. They had changed to nitrox at eighteen metres which usually helps clear one's head after being at depth, but Sherlock must be feeling the exhaustion more and more by the minute as adrenaline dissipates and his glucose stores deplete once again. Morten's honey won't provide energy for long, so Sherlock will be in desperate need of food and drink once on the dive deck. At least his breathing doesn't look like the shallow panting of panic; it's deep and regular, just a bit laboured.

"I'm switching my tank; keep an eye on him," John asks Morten, who nods and grips the shot line so that his arms encircle Sherlock. In the state he's in, he wouldn't be able to escape the Swede's bear hug.

John's regulator and tank changes go without issue, and the pure oxygen is like a breath of fresh mountain air when it hits his lungs. Breathing pure O2 will always cause some atelectasis — the collapse of lung air sacks — due to the large difference in oxygen content in the airways and the rest of the lung, but by breathing deep and slow, a diver can offset some of the effects. When he'd still been working as an A&E physician in London, John had noticed how often healthcare professionals forgot that oxygen is a medication and thus carries potential adverse effects — it's not a standard cure-all for all respiratory ailments.

John's dive computers tell him that he has four minutes of deco left. Rarely has he wanted to get out of water more; the buffeting they are getting from the waves above makes things worse. Morten checks Sherlock's computer and puts up three fingers with his other palm as a ceiling to tell John that's how many minutes Sherlock's computer has calculated they should remain at this depth. It makes sense that those calculations would be so close; their computers are of the same brand, using the same mathematical models, and their depth profiles on this dive are very similar.

There is little else for John to do during those three minutes but to watch his patient. _Yes, that's what you bloody well have made yourself_. Sherlock's line of sight wanders around their surroundings, attention never focusing on John or Morten for long. John likes what he sees; Sherlock is aware and interested in his surroundings, isn't shaking anymore, and his movements are less clumsy. _No aggression, no evident paranoia, no panic._

He's never been angry at other divers for getting in trouble — until now. But he's too worried, still, for that anger to bubble up properly, too focused on survival to let the full range of his emotions break through. _There will be words, though. There will be a very long conversation, and he's not going to like it._

John checks his computer, and soon enough, the indicator gives permission to surface. He isn't often bothered at all by the sight of the murky, dark, blue depths beneath him on a safety stop, but the awareness that those depths had nearly become their grave today is disconcerting.

His eyes catch sight of movement above. There's a new diver in the water, descending along the shot line, and John soon recognises from the colours of the gear that it's Dionisio. John curses the fact that he hadn't thought to ask for more backup — Morten must have left instructions for Dionisio to jump in when he saw the signal buoy.

John has to admit to himself he's been a bit single-minded and inflexible in his thinking during the crisis and the ascent — hyper-focused on Sherlock, and likely a bit impaired by narcosis and other effects of depth. _Everyone becomes a bit stubborn and slow down there._

"Good to see you, Dionisio," John calls out through his radio. "Come to give us a hand? Over."

He sees Dionisio reposition himself so that he's descending feet first; it's easier to maintain visual contact that way. "How is he doing? Over."

"Better, I should think. Surface swim's going to be tough, though. Over."

"We're down-current from boat, Jose-Perry's put out rescue floats. We can pull him out with one or tow him together, or you can help him swim to ladder. Over."

"We'll tow. I don't want to risk him losing his grip on a float and being swept out by a current. Over."

"Okay, John. Over."

Dionisio is now only a few metres away; the current is bringing him in fast, and all he needs to do is glide down the shot line. Once close to Morten and John and Sherlock, he stops his descent. He shows Sherlock the OK sign — it's a question, and he expects to see the same sign back. He gets it, though with a bit of a delay.

John glances at his computer and signals to Sherlock that their safety stop is over by sweeping his palm across his computer. Sherlock responds with the same sign after inspecting his screen. John slips an arm around Sherlock's waist and pushes the two of them away from the shot line; best keep away from it during their surface swim because it might buck them about on the waves.

They ascend the last few metres, spinning slowly around their longitudinal axle as they approach the raging waves to make sure there's nothing above them. When they break the surface, John is tempted to rip off his mask and breathe some real air, but it's safest to keep his mask on and rely on his tank until they're on the boat.

John inflates Sherlock's BCD before seeing to his own. He then passes Morten his nitrox tanks to clip onto his shoulder strap. Dionisio has only got one long regular scuba tank, so he has more room to spare; he gets both their oxygen tanks and Sherlock's nitrox.

Sherlock spits out his regulator. "What if the weights you dropped hit and damage the wreck?" His usually deep, honey-glazed baritone has risen in pitch, and he sounds slightly hysterical. "You shouldn't have––" the rest of the sentence is drowned out by a wave that hits him straight-on, leaving his coughing and spluttering.

John rips his reg from his hand and shoves it back into his mouth.

He then holds his own reg momentarily away from his lips. "Shut up and breathe!" _We can argue all you want once we're back on the fucking boat_.

He checks how much air Sherlock's small O2 tank still has. There's only about a quarter left, but it should get them to the boat. The Salaminia is battling the waves only some twenty metres away, and though the waves are uncomfortably high, the current on the surface isn't too bad.

"We'll keep him on the O2, over," John instructs through the radio, then removes his reg again, turning his back to the waves. "Sherlock, everything alright? No, don't take your reg out," he then commands; the waves keep crashing over them even with their BCDs fully inflated.

Sherlock gives him a tired OK sign. Even after he's been fed half the sugar on the boat, John will need to keep watch on him — should the man start showing signs of DCS. The risk should be low since they'd done all their deco stops, but DCS is a fickle bastard, and even when a dive goes without a hitch, no mathematical model can promise without any error margin that a diver can't be struck down by it. In some cases, no reason is ever found for a diver getting bent — it can happen even if one stays well inside established safety limits.

"I should tow," Dionisio offers. "John, did you hear me? Over."

"Yeah," John replies reluctantly. He knows that he should leave the most strenuous part of the surface swim — helping a stricken diver to the boat by towing them while doing a backstroke — to the least exhausted diver. It's just that a part of him doesn't want to let go of Sherlock. _I need to make sure he's alright. He's my partner and my responsibility._

"Save your energy, man," Morten tells John. "You could grab a float if you wanted. We'll help him up first; it'll be nicer for you to wait hanging off a float instead of being banged about by the ladder."

John waits until he's absolutely sure that Dionisio has a sturdy grip on Sherlock's shoulder straps before he lets his fingers lax from being practically convulsed around the man's isolation manifold. Dionisio turns his back to the boat, pulls Sherlock against his chest and begins finning towards the Salaminia, supporting Sherlock's head above the water with his arm while holding on to his shoulder strap. John watches them for a moment, telling himself he's just admiring the textbook technique, but if he's honest with himself, he's just finding it hard to allow himself to lose visual of Sherlock.

"Alright, John?" Morten asks with a reassuring smile. He's grabbed a float — a round, orange rubber buoy attached to a rope — the rope of which he offers to John. Morten does his surface swim right alongside John to keep an eye on him. John is too much a professional to let it grate on his ego that he's being escorted back.

 _Whoever has signed Sherlock's fit-to-dive certificate needs to have their medical licence revoked_ , he curses as he slowly but surely fin kicks against the current. _Unless Sherlock concealed vital information from them, too_. There is no universal health record system available for dive physicians to consult, so if Sherlock had his diving medical done abroad, the doctor would have been at the mercy of what his patient was willing to disclose. John wants to take a look at the Tresiba packages to see which country they've been prescribed in. He also wants to see what kind — if any — results of blood sugar measurements Sherlock has written down. _You'd better be as meticulous with those as you are with your research._ John wants, _needs_ , to know everything because, whether Sherlock likes it or not, he's got himself a doctor, now, for the duration of his trip. _Maybe I should put him on an IV, even, at least until his blood sugar level is stabilised._

Sherlock and Dionisio have now reached the ladder attached to the dive platform. Anderson, barefoot, has climbed down the ladder and is standing with his feet in the water, extending an arm. John is relieved to see that Sherlock readily accepts the appendage offered. _This is no time for embarrassment over needing help._

Sherlock begins scrambling up the ladder slowly, shakily, and soon Anderson and Greg grab hold of his isolation manifold to help him cope with the weight of his equipment. He slips once on the steps, nearly plummeting back to the water, but Greg's strong arms grab hold of his shoulder straps and pull him onto the deck. Sherlock should have kept his regulator on while on the ladder, according to standard dive practice. _He must be more shaken than he lets on_ , John thinks. He notices Mariza standing by Terry the cameraman, a huge glass of orange juice in her hand. Terry has his gear on his shoulder and appears to be filming. John doesn't like it; documentary or not, they should be focusing on more important things.

"Greg? You listening, over?" John calls out as he continues finning towards the boat, assisted by Terry pulling on the float rope from the dive deck. It's easier to swim back-first when in scuba gear, and that way waves don't hit one in the face.

"Right here. Over."

"Can you get someone to find a blood sugar meter from Sherlock's cabin? He's got to have one. It'll be a small, round-ish plastic thing, probably in a pouch somewhere. Over."

"You got it, John. I'll send Joseph. Over."

As the adrenaline begins to fade, anger is seeping into John's bones. _This could have been avoided_. Sherlock is an intelligent man; he must have known what medical diving recommendations say about insulin-dependent diabetes. _You knew, and you still dived. You knowingly put yourself and everyone else in danger._

He can't see Sherlock on the dive deck, now; the team has probably helped him out of his gear, laid him out on a towel on the deck with an oxygen mask after giving him the juice. _He'll need more food, something with a lower glycemic index that'll help rebuild his liver glycogen stores instead of being just a quick fix._ John tells Greg as much, and the man promises Mariza is on it. "He needs slower carbs, get him some of that wholegrain toast everybody hates––"

Greg is laughing on the radio. "Just get yourself on the boat, John, we'll sort it. Over."

By the time they reach the half-submerged ladder on the dive platform, John's thighs are quivering with exhaustion, and he's panting hard. Four team members are standing at the edge of the platform, ready to help, and they practically lift John out of the water. There are towels being held out, a water bottle thrust into his hand once he's ripped his mask off, the rubber straps tearing out some of his hairs.

By the time John plants his boot-clad feet on the dive deck proper, he expects to see Sherlock lying somewhere with an oxygen mask on his face. Instead, he's sitting up on a bench, fingers fumbling as he opens the straps of his dive computers and drops them into a water bucket reserved for rinsing gear.

"I'm quite alright, really, no need to fuss, we were well within the contingency margins of our plans––" he rambles rapid-fire with that odd, high-pitched tone John had made a note of earlier, "In fact, I need to document your—my f-findings as soon as—" he gets his fin boots off, then strides off towards the stairs, nearly tripping on the first step.

"Stop right there!" John commands in the voice he has rarely used since his army days, to no avail; Sherlock has left the dive deck.

John quickly begins struggling out of his BCD and isolation manifold, nearly dropping them on the deck. It takes him several minutes to get out of his things: his fingers are gone numb from cold he hadn't even noticed until now, his tanks need to be safely attached to something so they won't roll overboard, and his computers need to go in a bucket, too, to prevent salt crystals from forming and breaking them. His every sense is screaming to run after Sherlock.

"Can I help you with anything, John?" Dionisio offers.

"You can shove his gear into a trunk, lock it and throw it overboard — his diving's _done_!" John declares as he stomps around. "That fucking bastard arsehole!" John vociferates, and nearly slips on the wet deck while shoving his BCD into a heap in a box, not caring about being neat or orderly right now. He grabs an old, ratty white bathrobe hanging from a hook without even caring whose it is and slips it on. "Where's the glucose meter?"

Joseph gives it to him, and he shoves it into the bathrobe pocket.

"Didn't you want us to put him on oxygen?" Morten asks carefully; it's as though he's wary of John right now. "I told him so."

"Yes, I fucking still do. Where is he?! Didn't even one of you have the sense to go after him?!" John complains to Greg, who's standing uselessly by a tank of drinking water. His tone is as worried as it is bloodthirsty.

Greg shrugs. John glares at Greg.

"He said no to the O2. Can't force him, can we?" Lestrade excuses.

John _growls_ with frustration.

"Must have gone to his cabin. You… alright, John?" Greg asks, extending an arm to take John's last tank from him to be put away.

"No, I'm bloody well _not_ , but that's nothing compared to the shape he's going to be in once I find him. Get out of my way!" John barks, steps around Greg and marches to the front of the boat to get to the stairs. He ties the sash of the bathrobe as he walks, then breaks into a jog when he reaches the stairs. He takes them two at a time to get to the right deck.

Standing before Sherlock's cabin door, he tries to muster even a marginal sense of calm. His fingers curled into fists which he then opens; a nervous tick he knows he has. He sniffs, shaking with rage and adrenaline; the relief over both of them surviving the ordeal no longer overrides his shock at what Sherlock has kept from him and the rest of the team.

"Right, you fucker. _Let's talk!_ " He yells as reaches for the handle of the cabin door, but the handle slips out of his reach. The door has been left unlocked, and it's now swinging ghostly in the swell of the boat. The whole deck feels oddly deserted. _But where else would he go than his own cabin?_

John steps in, closing the door after himself. As he takes in the sight of the state the cabin is in, his ears pick up the sound of the shower running.

Sherlock's black wetsuit and its hood sit in a wet heap just inside the door. What looks like the shirt of a thin, thermal undersuit has been discarded on the floor next to the bed as though they'd been hastily pulled off while walking. There are books and papers scattered everywhere, and the bed looks so neatly made it must be Mariza's handiwork. Even the flowers John recognises as the ones she had left on all of their beds two days earlier are still on the pillow. There are two bags of white pills on the bedside cabinet; Greg must have gone straight to the ensuite and missed them. John picks them up and shoves them into his bathrobe pocket. He opens the fridge and finds the insulin packets. The package insert tells him Tresiba is a particularly long-acting insulin. It's a relatively new one, which explains why John hadn't recognised the name as fast as he would have many others such as Levemir or Novorapid. The only other thing in the fridge is two water bottles.

Standing by the bathroom door, John digs out the glucose meter from his pocket, turns it on and scrolls through the measurements. There aren't very many of them, and all of them are below 6.0. _Clearly, he's managing his diabetes in terms of having no hyperglycemias, but are the insulin doses he takes too big?_ John finds a measurement from the day of their first dive, just after they had come up. _2.1. Christ. No wonder he was acting weird. Does he really not measure it more often?_

John tries to look for another glucose meter, but there are none to be found. When the shower doesn't stop running after a few minutes, he knocks on the ensuite door. The bathrooms don't have locks for safety reasons, and John decides he can't respect Sherlock's privacy right now. There's a list of things he needs to get off his chest and to check and attend to, most importantly the fact that one doesn't leave a diving partner alone when they've just a close call with the Reaper Man. "Sherlock? I'm coming in."

There's no reply. _He must have heard me_. John opens the door, and the air leaves his lungs when he absorbs the sight that greets him in the bathroom.

Sherlock is stark naked, sitting on the floor under the warm spray of the shower, shaking violently, face buried on his knees and chest heaving as he tries to gasping for air.

John kneels down, his anger evaporated, not caring if he gets wet again. "Sherlock?" he asks and lays a palm on a bony, trembling shoulder.

There's a flinch, and a head of wet, messy curls is raised.

"Go _away_." The words crack and break; the repellant anger Sherlock had likely aimed for ends up being just a desperate plea. What little John can see of his eyes show that they are rimmed with red. Sherlock hangs his head, hugging his knees to his chest, breath hitching as he battles against an onslaught of emotion.

More things begin registering to John, now — things which he realises have been hidden underneath long-sleeved shirts and the wetsuit that is always put on in the privacy of this cabin. There's an old break in a collarbone which obviously might have needed an orthopaedist consult and maybe a plate put in. There are strange, small, round burn scars on the shoulders and finger-shaped clusters of bruises on ribs and arms. They are clearly weeks old, since the colouring is mostly green and yellow. Even older, scarred track marks which dot the crooks of Sherlock's arms become visible to John when Sherlock reaches down to rub his goosebumped shins. There are small nicks on his forearm, and John realises they're likely from blood sugar measurements. Diabetics who don't want to advertise their diagnosis have long used those alternate sites instead of fingertips, yet only recent studies have validated them as a plausible option. _But not in hypoglycemia. They're not as reliable, then._

John stands up and turns off the shower — the water is piping hot. Hypothermia is a possibility, but Sherlock's shoulder hadn't felt cold enough that it would explain everything. John has a sense that he's just been handed all the puzzle pieces he's been missing. He also realises that what he has now seen and what Sherlock has sought to hide has just made everything between them and everything he needs to do to help a lot more complicated.

He grabs a towel, holds it open in an invitation. Sherlock uncoils himself, rises from the floor and practically stumbles into John's arms as he takes a step into the inviting warmth of the towel.

John drapes it around him, rubs his arms and leads him to sit on the bed.

"I don't know what this is," Sherlock mutters, eyes wide with confusion and awe. "I don't know what's happening to me."

John sits next to him, shifts them both so that they're facing each other at an angle. He's seen this before: someone being able to function while still on the dive where something risky happened, then experiencing all the fear and relief and stress afterwards in a surge. "Well, let's start with you having just had both a hypo attack and a pretty shitty and scary dive and the two of us needing to talk about it."

"I don't get _scared_ when diving."

"Everyone gets scared. Hell, most people are a little scared on just the pool part of the beginner course. I worry about the ones who aren't."

"I don't. I don't accept the possibility. It can't happen, so I've turned it off."

"Turned it–– _off_?" John frowns. He's tempted to reach out, to wrap an arm around Sherlock's shoulders, but every bit of the man is signalling that it wouldn't be welcome.

"It's useless, so I don't allow it."

"You can't just tell yourself that you're not allowed to get scared. You need to unload what happened. This can't be your first adverse even when diving."

"That wasn't an emergency. I was completely in control."

"The _HELL_ you were! Look, we need to have a talk about the––"

Sherlock's shoulders sag as he gasps and buries his face in his hands, clearly trying hard to compose himself despite being so overwhelmed. John leans over the bed to grab a Blue O Two-branded fleece blanket from where it had been draped over a chair, wraps it around Sherlock on top of the towel. Sherlock is tense, and he resists John's ministration a little until John firmly pulls him against his side.

There's a knock. "You guys need anything?" Greg's voice comes through the door.

"Some of the toast, more juice, fruit, honey, whatever you've got with loads of sugar. And whisky." _Time is ticking at the need to replenish those glucose stores._

"Alright," Greg replies hesitantly. "He's not bent, then?"

"Don't jinx it," John tells him.

Sherlock has gone completely lax against him and mutters something into John's neck.

"What was that?" John asks, grabbing his gently by the shoulders to see his face.

"I don't know what to do. I'm so tired of this."

John has a sudden sense that he isn't talking about what had happened on the dive. _It's all coming tumbling down, now, isn't it?_ "Tired of what?" _Be clever and put the pieces together_ , John compels himself. _Why would he have cigarette burn scars on his shoulders?_

"You're not… using, are you? Those scars look old," John points out and reaches out to touch the raised, scarred veins on the crook of Sherlock's left elbow, but the arm is withdrawn before his fingertips make contact.

Sherlock shakes his head. "Not in two years. Not in ten years before that."

 _What happened two years ago?_ " Look," John says, "You probably don't think we're friends, and you piss on the whole concept of dive partners looking after each other, but I'm here to listen, and nothing you say will leave this room. I'm more than a bit pissed off at you for not telling me about medical stuff I should have known because it's my job here, but that's because I don't like to see people get hurt. What you did endangered others, too. I need to understand, Sherlock, and if you can explain why the hell you'd keep all of that secret, then I'd feel a hell of a lot better, too."

Sherlock's fingers reach to his shoulders to keep the blanket from slipping off, and John scoots backwards on the bed to give him some polite space.

A knock on the door soon brings in Greg carrying two heavy shots of Scotch, two large glasses of orange juice and a plate of various fruit cut into bits as well as six pieces of buttered toast with cheese slices.

"Not hungry."

"I don't care whether you are or not. Someone who carries a glucagon syringe should know the drill."

Obediently, Sherlock grabs a piece of banana, pries off the remains of the peel with trembling hands and eats it. John gives him the other whisky, which he downs with a grimace.

Alcohol is really not what the doctor in John would have prescribed for someone in Sherlock's state, but the seasoned diver who's seen a bunch of emergencies definitely would.

John indulges in a few pieces of fresh pineapple; he's burned through his breakfast, too. The whisky gives a nice, familiar burn as it slides down his throat. He hopes that it'll give him the balls and the patience he needs to finish this conversation they're trying to have, to stop circling the truth.

"Type one diabetes?" John asks calmly.

A shake of a damp curly head. "Secondary to acute pancreatitis two years ago."

"And the pancreatitis was caused by?"

A swallow and a deep breath. "Cocaine, which I haven't used since. The insulin doses I need are very small, which makes adjusting doses challenging. No insulin resistance."

John knows that, with diabetes brought on by another illness, the body's sensitivity to insulin tends to be quite normal. It also means that there is a very small safety margin between a safe insulin dose and a dose that's too big. "Do you get hypo symptoms you can recognise?" John is pretty sure he already knows the answer but wants to hear it from the horse's mouth.

"I used to, but lately, no. The last year has been… harder to manage. Other things on my mind."

John rolls his eyes. "Christ." Diabetics — of many types — can dive, but they can't have had a single hypoglycemic event in a year or spent time in a hospital because of their illness. If a prospective diver came for a medical assessment who had secondary diabetes with a narrow safety margin for doses and no warning symptoms, John would absolutely not clear them for anything else than lounging in a deck chair at their hotel. "Type one diabetics can often be cleared to leisure dive to reasonable depths but tech or wreck penetration... just no. Who told you that you could dive?"

"No one."

"But you must have had a new medical for the more advanced tec courses?"

"My original certificate was still valid, so that got me through the low-level courses. I didn't go to the same London-based dive physician I'd seen prior to the pancreatitis when preparing to do the higher-level tec courses; I knew I wouldn't pass the evaluation. I went to see a dive doctor in Thailand, instead, during a conference trip, and the instructor I chose for the rest of my tec training accepted the paperwork. I'm in control of this."

 _The fact that you're saying that demonstrates the opposite._ "The hell you are. Today, you certainly weren't. But what about dive insurance?"

"I plan meticulously, and nothing has ever happened. Don't ask, don't tell. I don't get bent."

"Like you don't panic and almost drown after going to hypo?"

Silence.

"You know that the insurance company would raise hell if they found out afterwards you were diabetic and concealed it. Probably even just your drug history might put them off." Any dive physician worth their salt would have required proof of sobriety before signing anyone off for even a beginner's course. Active drug use is a contraindication to diving. "Would you tell me if you were still using?"

"I told you — I don't."

"Then what's this?" John digs out the ziplock bags of tablets from his pocket.

"You obviously haven't look at them properly. It's Mirtazapine and alprazolam, and I can show you UK prescriptions for both. Sometimes the latter helps when I can't concentrate. They don't really work with sleeping, though. But I manage."

Alprazolam is a commonly misused tranquiliser. It shouldn't help anyone concentrate — unless they suffered from severe anxiety. Mirtazapine is an antidepressant. John squints at the tablets and Sherlock's explanation is confirmed at least as far as what the tablets contain.

John draws a breath. _Time to really poke the hornet's nest._ " Maybe you did manage, once, but maybe something's going on that doesn't have anything to do with this trip or your diabetes." He remembers that Andrew had also complained about Sherlock's habits changing around that time. That he'd become withdrawn. Joyless. All logical signs of drug use but why relapse after a decade of being clean? "You said that the last year's been tough, but what happened two years ago? Why'd you relapse?"

Blue-green eyes snap up to meet his, startled and wide. "What?"

"Something happened around that time, didn't it, something that's wrecked your mood and your self-care. If I saw those prescription bottles, I assume they'd be dated after that?"

"Don't––" Sherlock says, drops his gaze and nervously fingers the edge of the blanket. He's stopped eating Mariza's offerings and looks vaguely nauseated, now. "Just… leave it alone. There's nothing you can do." He drops to his side on the bed, facing away from John and closes his eyes.

John, still seated, plants his palms on the bed behind him and leans back. "There _is_ something I can do, which is to listen and help you work out what _you_ could do about it. It's the phone calls; they're about whatever this is, aren't they? Who is that? Who called you when we were at the hotel that got you so riled up you tried to bite my head off?"

The silence speaks volumes.

"What happened two years ago, Sherlock?"

"I met _him_."

"A relationship gone bad?"

"It was never good to start with. He's the CEO of the Hilti Foundation. If I don't… if I end it, it will mean the end of the Centre. He's already got us, the Centre, in a chokehold."

 _Looks like he's got you literally in a very personal chokehold_ , John thinks bitterly. Now that he's seen the evidence written on Sherlock's skin, it all makes sense. He drops down to lie on his back on the bed, pats Sherlock's arm which brings on a flinch and makes the fleece blanket slip down his back, revealing oddly shaped thin, sliver-like scars. John leans closer to see what the shapes are.

They're letters. I. O. U.

' _I owe you_ ' _? That doesn't make sense. 'I own you'?_ _Jesus fuck._

It hardly matters what the author of those letters had mean, precisely. What they really mean is that the diabetes just might pale in comparison to the bigger problems in Sherlock's life. "There are tons of other people and organisations who I'm sure would be happy to finance you," John argues.

"Not if they are given proof that funds have been mismanaged. Which they have _not_ been, but whatever proof is needed, it'll materialise if he decides it needs to be." Sherlock's hand appears from underneath the blanket to snatch a piece of mango. "I have to dive. I can't do my job otherwise."

"Uh, nope. But we'll get back to that later. Since when did professors even do their own fieldwork?"

"Gets me out of Oxford." Sherlock's tone betrays how much he wants to get out of there.

"Do you live with this person?"

"No, he lives in London. We never _lived_ together, it was just––" Sherlock turns to his back, his mouth an angry line as he pulls the blanket up to his chest. "It is what it is, and that's… complicated."

"You don't have to explain any details––" John starts, but apparently this needs to come out, now, since Sherlock ignores him completely.

"What you suggested at the resort — no, hear me out — what you suggested, I don't do that. With anyone. Ever. Do you _understand_? I don't want to, with _anyone_. I don't feel a need. I sometimes willingly participate because I would enjoy a partner enjoying themselves, and I like to think I would enjoy many of the other things, the… _relationship_ things––"

John nods slowly, mostly confused. He suspects Sherlock is referring to other physical stuff besides sex.

"I like that, some of it, if…" Sherlock trails out again. "But what you suggested that first night so bluntly –– I don't. He's never accepted that. Told me I just needed a bit of practice to get into it. I'd not been in a relationship before, and before him, I thought I knew what I want and what I don't want. He won't respect that. Eventually, he's made me doubt what I thought I knew."

"Then he's an arsehole." John can't really relate to someone wanting to banish sex altogether from their lives because they have no interest in it, but he also knows that a no is no, and it's wrong to question that or tell the other person they've somehow got it _wrong_.

"He won't leave me alone. He has other partners, always did, even when we were… maybe together is not the word, but he doesn't take to it kindly when he's not the one who decides to walk away. I tried once. How does that stupid phrase go? _Been there, done that, have the scars to prove it._ " He takes the rest of the whisky down in a savage gulp.

"He's a double-glazed arsehole, then. And he's holding the purse strings of the Centre? Christ."

"I can manage…the things we do. But I'll never want it––"

John raises up a palm. "You don't have to justify to me not wanting something." _Christ, this guy's done a number on him, hasn't he?_

A fury blinks into life in Sherlock's gaze. Maybe the whisky is lowering the man's inhibitions. "That's how people always react. They pretend to sympathise and respect how I feel, but secretly they're pitying me or convinced a round in bed with them will make me see the light. He's not the first to attempt to _cure me of this terrible affliction_. People make it out to be a disease or a choice I'm making just to spite them. An excuse to turn them down."

"So, you're…what? Asexual?" John is familiar with the term but can't boast knowing anyone like that. Then again, how would he know? _Would people tell Five Oceans Watson such stuff?_ He likes sex, likes everything about it — except perhaps the attached pressure for a relationship — so he can't quite fathom why someone would want just the relationship without any of it.

He shakes his head. Even if he can't relate, it doesn't mean it doesn't exist. And whatever Sherlock is or isn't, he shouldn't be having sex forced on him that he clearly doesn't want. For John, mutual enjoyment has always been his guiding light of an enjoyable encounter; he's pretty damned sure he can pick up on a partner's unease and has backed off many times when his enthusiasm hasn't been mirrored. He doesn't even need to hear a no to be able to tell things shouldn't move any further. How could someone just ignore all that and–– and–– just _plough the fuck on_?

"It's fine," he hastens to assure Sherlock. "It's all fine. Whatever your definition is, you have a right to it. No one should be telling you that you need to change it."

"It doesn't work that way. In the beginning, he exploited the fact that _my_ definition falls somewhere between asexual and being willing to accept certain things with someone they're romantically involved with. I didn't have enough evidence to estimate whether that might happen or not. Now I know that it very much depends on the person, and he's not it. I'm not discounting the possibility, but I am also not sure… He just told me it's not fair to string someone along while I try to decide; that I should just shut up and let him get on with it."

 _No one should be told to just 'get on with it', just like no kind of consensual BDSM breaks bones and leaves burn scars. What the hell kinds of mind games does this guy play?_ If John hadn't witnessed, first-hand, how relationship slowly turn sour, how the power balance can tip and shift, he would have dismissed the idea that someone like Sherlock could have ended up in such a position. John knows better; this is not about having no confidence or will of character; it's about the manipulative abilities of someone clever enough to finds the cracks and often subtle weaknesses in someone else and use them to their advantage. To make them believe the hell they're in is the best case scenario they could ever hope to find.

Sherlock's mouth has tightened angrily, which makes John wonder if he's tempted to defend this person. _Stockholm syndrome_?

"Right," John says, squaring his shoulder. "How do we get this fuckwit prosecuted? You said he lives in the UK, so…"

"I told you; I can't make a big deal out of this without at least having to being made into a scapegoat and resigning. He'd destroy my reputation and our work. I just have to… keep him at arm's length."

 _Sounds like this guy expects to have you a lot closer._ "By being on antidepressants and anti-anxiety meds and getting upset every time he contacts you? Sherlock… you've isolated yourself from everyone at work, you're carrying a huge burden of thinking the funding of the foundation lies on your shoulders, you're being stalked by someone who won't accept you don't want to be with them, you're risking your life by diving––"

"It's all I have." His voice is strained, and he's turned away from John again, raising himself on his elbow to drink more juice. "The Work is all I have."

John can hear the capital letter. "If it was just you that you were risking, I could walk away from this, but I can't." He rises from the bed, gets the blood glucose testing kit, and Sherlock offers his hand when he makes his way to that side of the bed. It's all out in the open, now, so John sees no reason not to use a fingertip for convenience. _4.2. He's going to be fine._

"There could have been three body bags on the dive deck today. You know it," John says gently, pressing a tissue he's grabbed from a packet on a side table to the fingertip.

Tears of utter misery squeeze suddenly through from under Sherlock's tightly closed eyelids. John would have never expected to see the man like this.

"The Work is all _I have_ to get away!"

"No. There's got to be a better way out of this. How'd you end up in a relationship with him in the first place?"

"As the vice-chair of the board of directors at the centre, I had to deal with him on a regular basis when he was elected CEO. He was charming, and I have eyes," Sherlock says defensively, as though John now assumes he doesn't even like _looking_. "I tried to keep it strictly on a business level, at first, but his stance is that he's not crossing any lines if those lines never even exist for him. At first, it _was_ about business, about my work, and we made some big plans for the Centre. I never expected it would be so difficult to extricate myself from what rather insidiously turned from a casual acquaintance to… Well, he probably has a very different definition even for 'casual'. When things began to develop strange... _tones_ , I was already in too deep to see it before I wanted out."

"Your collarbone?"

Sherlock won't look at him, but he nods.

"I'm going to assume that the cigarette burns aren't self-inflicted, especially those on your back. Have you got a camera?" John asks sternly.

"Why?"

"Look, this is probably the worst time to suggest we do this, but it needs to be done. You need to have it done, and I would wager a guess that it should rather be someone you know than the police or a nurse at an A&E."

"What are you talking about?" Instinctively, Sherlock drapes the blanket tighter around himself.

"You need photos of––of–– you know. Your injuries. So that you can press charges."

"No! I've just explained to you why I can't. Christ, you're an idiot! Everything looks old enough that he could argue there's no proof it even was him."

"You can press charges and you will." John knows there's a controversial law, or at least some precedent cases, which allow prosecution of sex-related injuries even if both parties claim there was consent. He'd learned this during a particularly strange patient case he handled at Holborn Hospital. "It's obvious he's terrorising you, and you can't live like this. With your credentials, you can get work elsewhere if the Centre topples, and I doubt the university would let that happen. I've seen you on the footage Anderson has shot; if you work a little on your tone and the snoot, the BBC would probably be thrilled to work with you again. You look absolutely phenomenal on camera, both in and out of the water. If the Hilti withdraws, and even if this guy fabricates some bullshit about funds being mismanaged, there will be someone else who picks up the slack. Especially once we go public with what we've found on our dives here."

"The... _snoot_?"

"You know, _'everyone else is an idiot, and I am the most charitable person who ever lived for donating my precious time to explain things to them_ '."

Sherlock snorts.

"I know there's still the issue with the publicity and the risk to the funding, but I don't think you have much of a choice, here. I've known people who've been in your situation," John says. "It's hard to fight back and hard to leave because you've been in the thick of it for so long you can't see what it's doing to you."

John's mother had been the perfect example, and his childhood is the reason why domestic abuse is his berserk button, always has been. "The photos will be only on your phone. No one else will have access to them. They'll be there to remind you that you need to look after yourself. I know what you said about the Work, but you can't go on like this. Don't let him win. Don't let him wreck _your_ life."

"You sound like a TV advert for a helpline."

"I'm fine with that."

Sherlock bites his lip. "Why can't you just let this go? It's hardly your problem. Just… stop _caring_."

"Believe me, during the surface swim, I was pretty damned tempted to do exactly that, but now, it's obvious someone has to, since you won't."

"It's a frivolity I can't afford. The Work needs to continue."

"Not at the expense of your safety and sanity, it doesn't."

Sherlock lets out a ragged breath. "This is just the hypo talking; I can't afford to be like this, I have to—" He trails out, closes his eyes. For a moment, all they can hear is the rocking of the boat on the waves, the hum of the air-conditioning struggling to deal with the tropical heat.

Finally, Sherlock sits up, drops the blanket and the towel, his shoulders hunching a little. He doesn't stand up, doesn't present himself to John, but it's an invitation nevertheless to get it over with. He tells John where to find his phone and how to unlock it, and without a word, John takes the photos.

The whisky helps John stay relatively calm as he documents the end result of what doesn't fit any of his definitions of love or a sane relationship. He's tempted to reiterate that point but doesn't want to stress Sherlock any further. _He's had enough of that in the past two years_. _This dive was just the last straw._

When John puts the phone away, Sherlock starts rising to his feet. "I suppose I need to go have a word with the others."

"No." John's determined hand on his shoulder pushes Sherlock back down to sit on the bed. "They can wait, and your health is none of their business, anyway, as long as you're not diving. Which is indefinitely."

Sherlock opens his mouth to protest.

" _No,_ " John tells him. "You're benched as long as I'm on the same continent. And right now, you're going to rest even if I have to sit on you to make it happen. We'll forget about the oxygen; I don't think either of us has a significant risk of getting bent, but we have to get you on a better routine of checking your glucose so we can work out the right insulin doses."

Sherlock slumps onto his back on the bed with a sigh.

  
____________

John's job turns out to be easier than what he would have assumed. After some more food delivered by Mariza and plenty of fluids, Sherlock's eyes flutter closed, and he sleeps for nearly all of the next fourteen hours. The only times he's conscious are when he wakes up to John taking his blood sugar level or shaking his shoulder to get him to eat something or when his bladder necessitates a visit to his ensuite. He drags himself off the bed, stumbles there and back, and collapses back onto the bed.

John suspects that the exhaustion his wrecked body and brain are finally crumbling under is not just that brought on by their dive or this expedition. John only leaves Sherlock's cabin to fetch a pile of books and clothes from his own, to negotiate about food with Mariza, and to have a word with Greg and Andrew about what's going on. He keeps his explanation economical; they now all know about the diabetes, so John can use it as a convenient excuse for what Sherlock has dubbed a house arrest with the first smile he's given John after their ascent.

With Andrew's help, John removes all of Sherlock's work papers and books and his laptop from the cabin to help avoid the temptation to get back to it before he's genuinely better.

While he sleeps, John gets restless, instead. It's hard to think about what he's learned and to be able to do nothing about it. Sherlock will need to be the one to extricate himself from this mess, and he's going to need help back in England to do it. _Does_ _he have friends there? Or maybe that brother of his could help?_ Somehow, John doubts that Sherlock is much of a social butterfly in his free time, especially after how Andrew had described him.

Late that night, John is sitting in a chair by the desk, reading a trashy, dog-eared adventure novel he'd borrowed from Greg when he thinks he hears his name being muttered. He's considered going back to his own cabin earlier that evening but thought better of it when Sherlock has become a restless sleeper.

He puts the book away, walks to Sherlock's side of the bed, only to find Sherlock still fast asleep. His hair is sticking up in all directions instead of just being flattered by the pillow; it appears the salty ocean air frizzles his curls up.

John prepares to return to his reading but gets startled when Sherlock suddenly sits up, eyes wide, and practically falls off the bed as he scrambles to the bathroom. Before John has a chance to protest, he closes the door, and soon, there's the distinct sound of retching from inside. Sherlock emerges relatively soon, wiping his mouth with some toilet tissue.

"You okay? Do we need to check your levels again?"

"No. Nightmare. And I'm not discussing it."

"Alright," John promises and forces himself not to give in to the instinct to fuss some more.

**Notes for the Chapter:**

> The issue detailed here about divers' health is fact: if you go abroad and deliberately omit stuff when filling out the questionnaires diving centres give you before they let you dive and don't actively disclose your chronic illnesses to dive insurance providers, you can get away with a lot. Don't do it. Those safety rules are not there just to keep you from dying — they're also there to protect people you dive with. They also protect your wallet: if it turns out you concealed a significant health issue, the insurance provider might refuse to pay for that 100 000 USD helicopter evacuation + hyperbaric treatment + ICU stay you needed because you got bent. In the UK, lots of scuba clubs running their own beginner programmes require a medical certificate and it's a bit harder to cheat on those. The only solution would be to have a worldwide electronic patient records system and dive physicians who refused to sign anyone off without having full access to all those electronic records… 
> 
> Secondary diabetes often doesn't quite work the way other diabetes types do, which allowed me a bit of artistic licence; some issues regarding how (fast) a hypo can be fixed have been altered quite a lot for happy plotty purposes. I hardly need to tell you this isn't a medical textbook…
> 
> The law interpretation John mentions [is fact](http://www.govyou.co.uk/consensual-bdsm-activities-should-not-be-a-criminal-offence/), and in some ways it can be problematic. For instance, it made it rather difficult to catch serial killer Colin Ireland whose victim pool was mostly the London gay BDSM scene since those involved in it wouldn't assist the police for fear of being prosecuted for activities of mutual consent.


	11. Alone On The Ocean

John crinkles his nose at the chemicals used in the boat's sanitation systems as he flushes the toilet and washes his hands. He yawns as he switches off the light in his bathroom, then pads back to his bed. It's only eleven in the evening, but he had slept very little the night before. Today, no one had even mentioned work or diving — the rest of the team had respected Sherlock's privacy and dedicated the day after a near-tragedy to rest and do some gear maintenance. Sherlock had emerged from his cabin for a short, presumably work-related conversation with Andrew, but stayed in his cabin otherwise. John had made frequent visits to check his glucose measurement results and advice on insulin dosing. Tresiba is taken once a day, so any changes to a regime are slow to take effect.

Strictly speaking, he didn't _have_ to watch over Sherlock all night, but… walking away from what he had learned just hadn't felt right. Pity is the last thing someone as fiercely independent, clever, and tenacious as Sherlock would want or need, so John has tried to push it away and think practically, instead.

_What happens when he goes back to Oxford?_

Had he chosen the right words, had he made any progress in trying to get Sherlock to understand he was more important than his work? Of course, John didn't want the worst-case scenario to happen with Sherlock losing his reputation and his job. Facing the potential consequences of a staged accusation of financial fraud would be no picnic, but he couldn't continue like this, could he? Lying back and thinking of England while hoping for the odd expedition to where that psychopath couldn't get his hands on him was no long-term life plan.

 _That's no life, period_. What did this guy even want with Sherlock? Couldn't he find someone else to toy around with? Or was that the entire point here — proving one's power by conquering the unattainable?

_Who the fuck is this guy?_

John doesn't doubt that Sherlock must have explored every angle he could exploit to get out, and if there was one that would spare him and the Centre from publicity, he would have found it. _Still, he can't stay in that travesty of a relationship just to protect the Centre_. John is suddenly reminded of a remark he'd heard his mother make to a neighbour who knew what went on behind closed doors in the Watson household: _'I can't leave him; what would happen to the kids?'._ It’s more than just Sherlock at stake. _If the Centre goes to the wall, there will be other casualties._

There's very little to nothing that John can do for Sherlock; he knows that. But he wants to know more, do more. _Where there's a will, there's a way, surely._ _Sherlock just needs to stop thinking he has to put up with this. Has to stop believing he doesn't deserve more because it's too much to ask for a partner to respect his boundaries._

John shoves his hands underneath his pillow and stares at the ceiling.

_What is it like never to feel the urge for sex?_

It's obvious that Sherlock's experiences with this fuckwit haven't made him the way he is, but they sure as hell haven't made things any better. John knows, as a doctor, of course he does that libido varies — that there are extreme examples at either end of the scale — but never before has he spared much thought those who are not on that scale at all.

 _Asexual._ John has can't quite imagine what that's like. Before, he would have thought that those people must be distant, unattainable, even cold, and while his first impression of Sherlock had been precisely that, there's so much more underneath. It seems logical to John that Sherlock would have developed a quick and brutal tactic to ward off unwanted attention.

_Maybe that's what boyfriend-of-the-year is all about: he saw a challenge instead of accepting Sherlock the way he is._

John knows that the way his own head — and his cock — function shouldn't be generalised to other people. _It's just that… it's SEX for fuck's sake! It feels good. Why wouldn't someone want it? God, it really is easy to slip into thinking that he's just not had any good sex, and that's why he thinks the way he does._

Then again, there's lots of stuff John isn't interested in, and he doesn't have to try them out to know for sure, does he? There's a whole host of sex stuff to which he would say — and _has_ said— no, thanks. And Sherlock's hesitant and rambling explanation had left a back door open for intimacy that isn't what people usually consider sex, hadn't it? Somehow, John doubts that the arse-for-brains who insists on forcing himself on Sherlock is a very keen cuddler.

Sherlock had never claimed to be repulsed by sex — only to feel no personal desire to have it for his own sake. He'd even said that he might enjoy… what? _Watching a partner enjoy themselves? Giving pleasure to them?_ It seems that there is a possibility he might reciprocate physical attention even if he did not want much, or anything, for himself. John likes to think there isn't much about sex he's not good at, that he knows the rules, that he's a considerate lover and is diligent in keeping up his skills with regular practice. But now, he's not quite sure anymore if he knows as much as he likes to believe.

Where is Sherlock's thermocline — the line between warm and cold, between pleasure and discomfort, the border between something that is welcome and something that needs to be rejected? Does that boundary stay the same, or shift like ocean currents, and how much has this person he's with shifted it? What _is_ considered sex in Sherlock's brain and heart, and what is not? John has always been willing to plunge right down into the proverbial depths, but has he missed out on the sights along the way? Admittedly, his bedroom exploits of late have become a bit… routine. Foreplay is just that, a quick thing to ensure lubrication to get over with, followed by the _pièce de résistance_ of a solid fuck with a climax, after which awkwardness descends like the dust puffed up by the bed banging against the wall. John has always felt a strange sense of dread at that moment, a sense of not knowing where he stands. Having sex proves that his body and its function have been deemed acceptable by a prospective partner, but after an orgasm, what's left? Just him, John Watson. _If there's no sex, there's just… what? The intimacy?_ Something about that thought makes him feel uneasy and exposed. He's probably been so focused on intimacy as a means to an end that he's never considered it could be an end in itself — something worth cultivating, developing and enjoying for its own sake.

He knows he shouldn't care about or dwell on Sherlock Holmes' love life, but suddenly, a whole new set of questions and possibilities has opened up, things he's never considered. His initial approach of trying to get something as crude as a "leg over" feels quite embarrassing, now.

Sherlock is strange and complicated. He is so different from what John has sought out before.

And he _likes_ it.

_________________

At breakfast, John finds Sherlock sitting at a corner table with Joseph, both with a plate of pancakes and fruit in front of them. John receives a similar plate from Mariza and takes it to the sofa area at the back.

Just as John is walking past their table, Sherlock looks up from his laptop and meets his gaze. "Five point two this morning."

"Good. Don't add another unit until we see tomorrow's result," John replies with a smile.

Sherlock opens his mouth, but for once, John can anticipate the conversation. "You're still not diving."

The disgruntled look he gets makes him chuckle.

Greg has already taken over half the sofa and is having a breakfast beer — one of his regular bad habits. "Morning," he greets John, then cranes his neck towards the dinette to make sure he's not being overheard. "How's Holmes?"

John leans against the backrest, relishing the sight of the still, sunny sea. "He's alright. A bit shaken, as anyone would be. Best not grill him about what happened, yeah?" he adds, giving Greg a stern look. "If you're considering putting any of the rescue footage in the film––"

"We're not. It would raise questions that fall under his private medical issues, wouldn't it?"

"Yeah." John draws a deep breath. "I won't go into details, but he's not diving any more on this trip." John could have also said that _he isn't diving any more, period,_ but that's between him and Sherlock.

Greg regards him quietly for a moment before asking, "You okay?"

"Yeah. Considering. I don't like almost losing people any more than I like really losing them."

"I hear you."

John fixes his gaze on the horizon. _Best not to dwell on what happened. Sherlock has more to consider when thinking about what happens in the future._

John hears footsteps and the sound of Sherlock talking to Andrew, followed by the closing of the salon door; they must have left the dinette.

This allows John to do some fact-finding. "Do you know anything about the Hilti Foundation?" John wishes they had an internet connection out here; he would have googled the name if he could. Greg knows people, so maybe the guy Sherlock is involved with is on his radar.

"Some. Why?" Greg is squinting in the bright morning sun.

"Anything about the CEO? Anything dodgy?"

"I know _of_ him, but that's it. Tabloids love him; guy's got a penthouse here and a penthouse there, and he's a regular in the major leagues of charities that have something to do with nature and history. I guess marine archaeology would make sense, be something his PR department might have suggested for a bit of greenwashing since he got his money from oil. Actually… hold on," Greg says hastily and disappears down a staircase towards his own cabin.

After a few minutes, he emerges with an issue of National Geographic in hand. ' _Preserving our planet for the next Millennium'_ is the headline on the cover, superimposed on a holographic image of the planet. "There was an article about the big players in conservation, and the Hilti was one of the foundations featured." Greg is leafing through the pages. "There." He gives the magazine to John.

The Hilti has received a full spread, and its CEO is on two of the images. ' _Millionaire entrepreneur, activist and philanthropist James Moriarty'_ , the tagline states under the headshot. The man is close to Sherlock's age, with short, blackish hair, piercing eyes and a smile that's as warm as a glacier. John is reminded of a shark. In the second image, James Moriarty is making his way up the steps of a building at the Greenwich Maritime Museum with another man on his arm.

 _Sherlock_.

He is dressed in a sleek tuxedo matching Moriarty's, curls schooled into a luscious, shapely cloud. Only the left side of his face is visible, but John can tell he isn't smiling. They hadn't printed his name. _That's because Geographic is not some society gossip rag; they wouldn't have given a toss who the CEO's arm candy is._

John checks when the issue had been published: two months ago. The caption under the image states that the Conservation Gala was held two months prior to publication.

 _Some of Sherlock's scars appeared to be much older than that._ He was still attending functions, being seen with this guy just months ago when it's clear that the relationship had turned bad much long before. This is how scared he is of this man and how desperate he is to preserve his life's work.

Anger surges in John like a riptide. "What's the talk on the town about the Hilti? Any financial trouble?"

Greg's brows hitch up. "No. As a matter of fact, they've been increasing their funding for lots of old projects and taking on new ones."

"Including the Oxford Centre for Maritime Archaeology."

"How do you know that?"

John nods towards the back of the boat. "Sherlock."

"Why are you suddenly so interested in this?" Trust Greg, an award-winning journalist, to sniff a story.

"It's complicated, and the people involved need... protecting. Can you please not say anything or dig into this yet, even if I've now got you all tempted?"

"For you, I'll sit on it, but not forever. It's not every day someone starts asking questions about the likes of Moriarty."

"It would be a disaster if someone found out where a tip that leads to a story about him came from. Trust me. You don't want to be responsible for the consequences."

"Alright." Greg looks puzzled but relents.  
  


_______________  
  


  
Though there is no diving that day, the boat is on the move: Morten's equipment has been set up once again at the aft, and John feels as though they are combing through every inch of the parts of the Graveyard they have not yet surveyed as well as the deeper waters between Isla Ruina and Isla Fuego. First, a cursory sonar sweep is used to compare crude topography with army maps and dive logs. Several larger structures are identified at the edge of the highest parts of the submerged table mountain which reaches up between the islands. There's a lot of pacing and muttering a pounding away on his laptop as well as complicated calculations run through what looks like barebones rendering software as Sherlock the initial sweeps to identify potentially interesting areas. Any sonar shadow that could be a ship is compared to historical records, and if the vessel can be identified as a relatively recently sunken one, its location is carefully recorded by Andrew before the sweep continues. Sherlock quickly loses interest in anything that's not spent at least eighty years at the bottom.

John stays out of the team's way but hangs out nearby; the others likely think he's keeping an eye on a patient, but in reality, he's mostly there because he loves watching the map work. He comes alive as he gets to use his analytical prowess, his encyclopedic knowledge of history, his engineer-like grasp of ship design and his ability to spot things everyone else misses. _He'd find even a needle in a haystack._

When what might be a wreck cannot be identified from written sources, Sherlock assigns Morten to use his sophisticated thermally sensitive side-sweep sonar, the results of which are then run through what Sherlock had described as shape-from-shading filtering. Creating the resulting images make their computers groan with agony since there is so much data to process, but the results are spectacular. In one of the images, they can make out the distinct shape of a bicycle on the deck of a small, sunken ferry.

"What are you lot even looking for?" Greg asks Andrew in the late afternoon. They are anchored by some rocks off Isla Fuego for dinner.

"I'll know it when I see it," Sherlock quips over his shoulder and hunches over his papers and printouts again.

Marica shakes her head as she tries to find space on the dinette table for her chiles rellenos and pepian. "You'll get sauce on your papers," she warns Sherlock. "Move."

Sherlock glares at her in that almost shocked way of his when someone dares to tell him to accommodate others.

John slides onto the bench next to him and loads a plate with the dinner offerings. "You've been at it all day; take a break."

"Is that a friend suggestion or a doctor's order?"

"It can be both."

John is disappointed and tries to hide it when Joseph joins them. Then again, there's no privacy for conversation in the dinette. And what would he have even wanted to say? His conversation with Sherlock feels unfinished, in limbo. He wants to offer to help, but… how? Now that Sherlock is back in work mode, John doubts he wants to revisit that moment of weakness when John had been simply in the right place at the right time to learn his secrets. _If that dive from hell hadn't happened, I'd be none the wiser_ , he suspects. Or would he? He still believes that Sherlock's endurance has its limits. All those things would have come to the surface eventually. Then again, John had watched his mother and his sister endure years of abusive relationships, and his mother had never left. Harry had been able to find an out when a work opportunity offered itself and her partner hadn't wanted to move.

_What would it take for Sherlock to put himself first? I need to talk to him, but how?_

Sipping water, he steals a glance at his companion. After two days of regular meals and plenty of rest and re-balancing of his diabetes, he seems to be burying himself alive in his work again. He seems to love it genuinely, but work is not the same as having a person in his life. Someone who supports and appreciates him. _Everyone deserves that, don't they, if they want it?_

John has been fine without. Just fine. It's all fine. He's got his life on Malta; it's a choice, the way he chooses or doesn't choose to have proper relationships.

Why is he so adamant, then, that Sherlock deserves such a thing — one that doesn't leave bruises on his hips?

  
_________________

In the next two days following what John has dubbed ' _the incident'_ since he doesn't want to be too dramatic _,_ Sherlock's behaviour changes — at least towards him. Instead of spending all his time holed up in his cabin and crankily bossing people around, he shows up for every meal and subtly seeks John's company and attention when he's not working with his team. It almost seems that, whenever he's in the presence of others, John showing up makes him visibly relax from the wound-up bundle of raw nerves he often seems to be when having to deal with the stress of interacting with many others at the same time.

John doesn't know what the consequences of their conversation on the day of the _Ormancey_ will be, or what the photographs now on the hard drive of Sherlock's phone will lead to. John reminds himself that Sherlock is the one who has to make the hard decisions; John can't force them on him before he's ready. _It's his life_ , John keeps telling himself, no matter how urgently he wants to drag the man away from it to safety. John knows he should take a step back, especially because his family history makes him prone to crusading about this. The expedition will be over soon, and his responsibilities will end.

 _Should I try to talk to him again?_ He wants Sherlock to at least understand that it's alright to discuss such things, that John will keep his confidence.

While Sherlock now seeks John's company and attention, he doesn't initiate conversations about anything but their work. While John loves hearing his enthusiastic mini-lectures about their discoveries and their historical significance, he imagines that they both feel as acutely the oppressive sense of what they are _not_ discussing.

One evening, Sherlock takes a seat beside John in the otherwise deserted dining area. John is changing the battery of his spare dive computer. Sherlock isn't carrying anything; not his laptop, not any papers. John suspects he may have been looking for him, but of course, Sherlock would never admit it.

"I don't want to go back."

A simple statement.

"To the pier, to Oxford, or back… in general?" John opens the knife part of his Leatherman and screws the plastic battery cover back into place.

"I don't know. I don't want things to change when it comes to my work, but my current situation isn't viable. You told me as much. But, I think it's weak, just running away, avoiding the truth. I don't _want_ to lose the Work.

"Could you take a leave of absence from the Centre?"

"And do what?"

"Maybe the point is not to decide on that beforehand. Just take a sabbatical." _Go where he can't reach you. Disappear. Take time out of mind._

"Did you decide on that before you left the UK for a diving career?"

"I mostly just told myself that I didn't know where I wanted to be or what I wanted to do, so I shouldn't tie myself up to anything. I was at a stage where I should have committed to one path in medicine or just locum, and doing that enticed me much less than diving."

"I thought people changed their lives because they knew what they wanted."

John chuckles. "You'd be wrong." Then, his expression grows serious. "One thing I do know and what you probably know as well is that you have got to get rid of this Moriarty guy."

"And destroy the Centre. There are other people involved; it's not a one-man-band."

"The Centre is not you, and if protecting yourself means letting it find its own way without you, that's what you have to do. I doubt that'll even happen. It's _Oxford_ , not some small backwater university."

"You don't understand. Walking away — especially if it's under a cloud of suspicion — would be toxic to any future academic work. He's already threatened that. It might be different if I had something concrete, something like the Drake ship, to use any excuse to stay out here, to build a career away from the Centre. Maybe I could convince the Guatemalan National Museum to insist that they be the ones to survey this area, not a foreign team. I know these waters, now, maybe they would consider…"

"Would that be a clear enough signal to Moriarty of what you want or don't want? Doesn't sound like he listens to reason." It sounds like Sherlock is grasping at straws. Does he have it in him to break away from that trap if it has to happen at the expense of his position at the Centre? John doesn't really know him, does he? Maybe he _is_ one of those public school boys who do what they're told, who go from one school to another, building an academic career, never stopping to think what it is they actually want. Does Sherlock have it in him to prioritise something else than work? He doesn't do it out of duty, at least John doesn't think so. _He does it because he loves it, and it's all he's got._

"You don't strike me as the sort of person who does what others tell you to do," John tells him. _'I have eyes'_ Sherlock had said, signalling that there was something about Moriarty he had felt drawn to, at first. John wouldn't be surprised if a part of this thing with James Moriarty had been some long-overdue rebellion, a prickle of Sherlock's dark and reckless side shining through.

It's as though Sherlock has read his mind. "He was… different. He made me _think_ differently. I mention the Yongala, and the next morning, he's holding first-class plane tickets to Australia, with all the arrangements made for tec diving the Queensland coast. He was in a position to give me everything I wanted, professionally."

"Except for the right to decide what you _didn't_ want."

Sherlock averts his gaze, aimlessly picks up John's dive computer and glances at the screen then puts it back on the table.

John tries to explain. "There's a type of rich people who come into diving centres, family in tow. Guy signs up for a beginner course, buys all the gear right away for the whole family. Wife doesn't want to dive, she's horrified, the guy's just amused. It's just another feather in his hat, diving, and he wants all of it, right now, no expense spared. Doesn't get that experience can't be bought. ' _Just take me down there, get me some wrecks_.' The family's just another thing they bought, just like the diving, they like having things, but they don't like it when those things require their attention or cause them trouble. I don't know if I'm making any sort of an understandable point here, but I think there's a type of men who behave the way you describe, and they give me the creeps. Must be nice to be the subject of that attention at first, though; it lures you in."

"Before long, you're used to it and feel like you've already been bought. It was all so... _insidious_ ," Sherlock muses.

"Look, when I did my stint as a GP I met plenty of people in––" he doesn't want to say _abusive_ , doesn't want to embarrass Sherlock like that or spook him away, "––bad relationships. None of them would ever have ended up in that situation if the other person had shown their true colours right away. Everybody thinks they have enough of a sense of self-worth never to let themselves end up like that. It's a vicious circle of good times and shit times, and the good times always come and make you think that it's all going to change. You hope it will, even though you know it won't. They make you feel like it's a bargain when in reality, it's a deal with the devil where you always lose."

"You gleaned all that just from a few encounters with patients?"

John draws a breath, reaches out for a half-empty carton of tomato juice someone has left on the table, and drinks from it. "No. I lived it, as a kid, but it took those patients to understand why Mum would end up in all that. She was a strong person, but not when it came to Dad."

"How did it… end? How did she get away?"

"You're assuming she did. Dad died when I was twenty. Car accident; driving drunk. She never left him. At one point, I just had to take a step away, to stop worrying for her life. I left for uni and never looked back; my sister resented and still resents me for making a clean break. I had to give Mum some responsibility for the choice of staying, but I do understand now how and why leaving was too difficult. There's this idea, this… theory that it's actually the person who does all the shitty things who's the more dependent of the two. That they need that co-dependence because they don't believe anyone would be with them unless they had been rigged to do so. I'm not saying it's a very conscious process, forming that sort of a relationship, but it's a pattern. Yeah, that's a good word. A behavioural pattern one can choose to want to learn how to break. It's just––for those people, it works. For the v––" he'd almost said _victim_ , "one under fire, not so much."

Sherlock is listening intently, absorbing every word.

"Then, there's a smaller group of abusive partners who don't have that logic behind their behaviour. They're just… born that way, I think. Judging by what you've told me, I don't think Moriarty will let you go without a fight. I think you need to prosecute. Otherwise, he'll never step back. Get a restraining order while you're at it."

"You've given this a lot of thought."

John nods. He can't be sure if his advice is right or good, but he can't not give his opinion. "Make it public if it's the only way. I know that's the worst part, but if you want to separate what happened with him from your work, you need the public pressure for him to be put under scrutiny by the foundation."

Sherlock swallows. "I couldn't. It's easy for you to say these things when it's not you who would be forced onto a witness stand or you who had to resign to save the legacy of your work. It's not–– I don't want any of it out in the open."

"Who the hell would?" John leans back in the white plastic chair. "If you need help with that, someone with all the press connections and who knows how to try to cordon this thing, talk to Greg. You can trust him. I promise. I'll give you his number. He may be an insensitive arse sometimes, but deep down, he's one of the good ones. Just… please, Sherlock, don't be alone with this. I know it must be damned frustrating to listen to advice from someone who's not in the thick of it, but maybe an outsider sees what you don't, which is how deep you've sunk with him."

Sherlock looks away. He untucks his legs from the bench he'd perched on, stands up to stretch his palms towards the ceiling. Then, he leaves for the stairs.

John can only hope some of what he's said has stuck.

________________

The next morning, preparations are made for John, Joseph, Morten and Anderson to dive. They must pick a site — with their days on the expedition becoming fewer and fewer, they must pick sites to dive before time runs out. Sherlock hasn't seemed too excited with anything they have found on the sonar even though Andrew and Morten have seemed rather hopeful of a few wreck shapes they've identified. Big certainly doesn't seem to be the word of the day — Sherlock appears more focused on what looks mostly like piles of submerged logs.

Frustrated and in a bad mood, he tells Andrew to _pick a bloody wreck if you so insist on rushing the Work_ when he's asked for the third time where they should moor for the day's first dive.

Andrew and Morten hem and haw over the sonar maps, and eventually pick a sheltered spot north of Isla Fuego at the edge of the submerged mountain.

The preparations on the dive deck are done mostly in silence. Gone is the banter and the carefree atmosphere. Sherlock doesn't come down to the dive deck, but John does spot him on the deck above, watching them assemble their kits.

It's important that John gets back into the water today; the longer he waits, the more nervous he'll get. _Experience doesn't make one completely immune to cold feet after a near-accident, and there's always something to be afraid of_ , he reminds himself when he feels a bit silly getting nervous over something he does for a living. Fear is a warning gauge as important as those on his dive computer. As long as it doesn't paralyse him, it keeps him alive and safe.

Thankfully, the dive goes without incident, and John hopes Sherlock will enjoy the footage, drawings, images and laser scan data they get from the wreck — the only downside is that Morten tells John via his writing slate that he suspects the ship late nineteenth century. Anderson was visibly excited to get back in the water, and the handsome underwater topography of the site had likely produced some attractive footage.

Once back on the boat, John's optimism turns out to have been naivete. Sherlock is on the warpath after discovering that one of their last diving opportunities had been wasted what turns out to be a Mexican mackerel fishing boat which had sunk not ten years ago.

He gets rather vocal about the fact that he isn't content with the modelling that's been used; he says he wants to spend time tweaking the data some more, because he's convinced that they have missed something important. John wonders if he's after Drake's ship; maybe this will help the man salvage his sense of pride in what must have been a pretty rough time emotionally.

After listening to Sherlock boss about his team for two hours, John is tempted to ask if he's checked his blood sugar since he's in such a foul mood. There are no visible physical signs pointing to hypoglycemia, but it's best to be on the alert. 

John stops him in the stairs and opens his mouth, but before he can form a single syllable, Sherlock has read his mind.

"Five point eight and _stable_. My dislike of incompetence has nothing to do with my glucose level."

John raises his hands in supplication. "Fine!"

He follows Sherlock into the upper deck salon where Morten and Anderson are working with their camera gear, and Andrew has set up shop for combining visual data with the depth readings he has input into some sort of a statistics program.

John pours himself a glass of red wine and sits on a barstool.

"Don't do the full renders, just the basic side-sweeps," Sherlock instructs his student.

Morten plants his bottom on the chair next to John, beer in hand. "He can grill Andrew now," he says, sighing and shaking his head. "We need to decide for diving spot tomorrow, but the prof won't settle on even a general area. He say we shouldn't jump to conclusions without putting together all the pertinent data."

John thinks that sometimes, these young scientists sound a lot like their professor.

John looks over at the tall, lean figure bending over the computer screen with Andrew. "You think he's looking for the caravel?"

Morten looks sceptical. "Drake's caravel? Nah, we have no way of knowing where it would be, no guarantee it's here inside the island circle. Why not on the outside of the big islands, it could have hit rocks there." Morten strokes his beard thoughtfully.

"Maybe Sherlock thinks they sought shelter in the lagoon."

John thinks back to what Sherlock had said on camera about wanting to be a pirate. He's not the first scientist John has met whose boyhood dreams and interests had turned into a profession. Maybe those treasure hunts of his childhood games had never quite ended.  
  
  
  



	12. Safe Harbour

Morten's frustration is transmitted through the radio.

"I have no idea what we're even looking for," the PhD student grouses, hovering in place over a barnacle-covered plank mostly covered by sand.

John vents a bit of air from his BCD. He's been idly poking around some seagrass to see if he could find a nudibranch or even a sea horse to amuse himself while the scientists work — the wreck they are examining is little more than a pile of wood on the sea bottom, and there's only so long John can maintain interest in it. "Sherlock didn't give you any specific instructions?"

"There's no way to know how old this wreck is, or who built it, not without radiocarbon and Joseph's microscope."

"The professor can probably say," Joseph suggests. He's jotting something down on a writing slate before tugging Anderson's sleeve to ask him to film something on a plank.

"Well, he's not here, is he?" Morten sighs and restarts his joyless laser measurements.

John won't bother even trying to guess what used to be a part of the deck or what belongs to the hull. He thinks he can make out where the masts may have stood since bits of them are scattered diagonally from the rest of the remains. It does look like a ship, but what kind is something which not even the PhD students are willing to speculate.

John pities Anderson: the man is recording footage here and there with no enthusiasm at all; this debris field isn't anything one would put in a spectacular diving scene in a documentary. The only chance this woodpile has of being in the film is if it has a lot of historical significance and it gets complemented by some 3D rendering wizardry is added to help viewers imagine what it had once looked like. The wrecks they have dived earlier during the expedition will undoubtedly be the stars of the BBC footage.

The site had been selected by Sherlock, based on something only he seemed to consider significant among the many areas of wooden wreck debris dotting the sea bottom in and around the Graveyard.

John finds Anderson a colourful coral trout to film; it's building a house between some rocks and purposefully puffing out sand and silt.

They spend an hour and a half documenting and digging around in the dull landscape of dark green seagrass and white sand — there is no coral growth in the spot. It's a spot Dionisio says must experience quite a complex system of currents from several directions; Sherlock had explained that the effects of the currents must have preserved the wood better than in other areas. Wrecks in very few saltwater areas are spared of pileworm, also known as shipworm. The Baltic is a treasure trove of wrecks for that reason; the worm doesn't seem to enjoy the relatively low salinity there.

Once done, the team returns to the boat, all keen for lunch. All seem relieved to get out of the water.

Sherlock is standing on the dive platform, looking antsy and expectant. Greg is behind him with his hands in his pocket.

"Tell me _everything!_ " Sherlock demands the moment John and Morten grab the ladder, preparing to climb onto the boat.

"You didn't miss out on anything," John says. "At least Morten doesn't think so."

"I'll be the judge of that," Sherlock says. His fingers, resting by his thighs, are in constant motion, patting his trousers. _Nervous stimming_.

John wonders if he's impatient to see their data or just generally anxious as the end of the expedition draws near. The evidence seems to point to the former since Sherlock won't even let his science team eat before commanding them to retrieve the data from their instruments and the footage from Anderson's camera and putting it on a USB stick for him.

"I'm not the expert, and I know you haven't seen the footage yet," John says to Greg over spag bol; "whatever that was down there, I doubt anybody's going to put it on the cover of NatGeo."

"Professor Holmes won't say what he suspects," Andrew points out from the opposite side of the table, "but he didn't dismiss this one right away like he dismissed better-preserved wooden wrecks we saw in the sonar readings in this area."

"How can you tell they're wooden?" Greg asks.

"Thermodilution scans, combined with laser reflectivity," Morten explains.

Suddenly, footsteps sound on the stairs and Sherlock emerges, slightly winded so he must have run from his cabin. "Stop that nonsense right now; we need to get back in the water. _Now_."

"Food isn't nonsense. Surface interval, remember that from your open water course?" John jokes and gets a glare.

"Your dive was shallow and well within safety limits. We can stretch the rules a bit."

"Who's this 'we'?" John asks, wiping sauce off his mouth. "You want the same team to go back down?"

"I'm coming as well."

"Sherlock, no. We talked about this."

John pins him with his gaze. _Do you really want to have this out in front of everybody?_

"John, a _word —_ alone," Sherlock commands and turns to go.

"Oi! Not your hireling," John jokes but climbs to his feet all the same.

He follows Sherlock to the man's cabin. There, Sherlock shoves a heavy book into his hands and lifts up his laptop to show John an image of a plank from the edge of the wreck debris. John can make out faint signs of holes in the wood — nothing else of interest.

In the spread Sherlock shows him from the book, he can see a picture of the seaworthy copy of the Golden Hinde, Sir Francis Drake's galleon, moored at its permanent spot in the Thames near London Bridge.

After offering John a few seconds' eyeful of the Hinde, Sherlock pulls the book away, slams it shut and stabs the laptop screen with his forefinger. " _Look!"_

"At what?"

"God, you're such an idiot," Sherlock growls. "The _nail holes_!"

"Nails…?"

Sherlock draws a deep breath, then launches into a verbal assault. "There are written records describing the caravel Drake was rumoured to have taken through the Strait of Magellan, but no paintings of it remain. However, several sources suggest that the same shipbuilders who constructed the Hinde built that caravel, and their trademark was an emblem at the back of the ship. Look at the configuration of the nail holes and the direction of the planks in that flat part of the pile, John! Just _look_! It's obvious that the vessel this wreck used to be was round-bottomed and had three masts. Those features, compared with the level of disintegration, and clear signs of an emblem at the back the exact size and shape also used in the Hinde––"

John has no idea how Sherlock can glean all that from just a pile of scattered wood. He remembers the description he'd heard of Sherlock's ability to reconstruct things in his head, to imagine what things looked like when they hadn't been broken apart by years on the sea bottom.

"The _Livro Primeiro de Architecture Naval_ specifically mentions that the British of Drake's time modelled their caravels after the Portuguese — except for the back, which was a cut-off design with an emblem eliminating two smaller windows. Nobody else did that, John! _No one!_ And who else than Drake could have made the journey? The _Livro de Traças de Carpintaria_ confirms that Drake shifted to a caravel design for ease of navigation in the Chilean archipelago instead of using a Hinde-like galleon design. If Drake's ship is down there, it has to be this one! When you eliminate the impossible, what remains, however improbable, must be the truth!"

"Alright, alright. You don't have to convince me."

"Yes, I do. It's imperative I convince you of its importance because I have to see it myself, John. I _have_ to dive." It's an urgent plea.

Sherlock puts the laptop down, retreats to standing by the door to wring his hands. He's avoiding John's gaze as if fearing a dismissal of his request. "I know there's been a lack of trust brewing in my habits and judgement over the past year among the students. The others on board here will side with you if you say no, but I need you to believe I wouldn't ask if it wasn't important! Up here––" Sherlock taps his head with his forefinger, "––I may be distracted and… overwhelmed, but I've got it, John, I've still got it, and I _know_ I need to go down there."

"But the thing doesn't look like much underwater! It's just–– just bits of wood."

"You and the others don't know how to see it the way I will. Seeing it through the eyes of others or just on film is not the same, and you _know_ it. Would you settle for watching Blue Planet instead of diving?"

John nods towards the book and the laptop. "You could give me any old nonsense strung together, and I'd lap it up because I'm not the expert. You _want_ it to be Drake's ship. Can you be objective about this, given how important it is to you?"

Sherlock is almost shaking with agitation. "Do you honestly believe that Howard Carter felt entirely indifferent when he peered into the antechamber of Tutankhamen's grave for the first time, do you? If I didn't believe in this, why would I have wasted all our time looking at those _bits of wood_? You think I'd risk my professional reputation on a wild goose chase? That's what many told Carter and Carnarvon they were on and look at the results! Whatever this means to me, it means _more_ to history!"

John lets his head loll back in defeat. _I wanted to make this happen for you. I wanted to see you find this, assuming_ _the wreck is what you think it is_. John is tempted to suggest that Sherlock could send him down with a GoPro, but he knows his protests will ring on deaf ears. The look Sherlock gives him is desperate and pleading, all of his snide superiority and the commanding presence he'd exhibited in the dinette gone.

 _It's a shallow dive, and Sherlock's blood glucose levels have been fine_. John knows he shouldn't do this, but…

"I know what you said about not diving. I'm at your mercy," Sherlock admits. "This is your call."

John hates him for saying that. He hates having to be the one to decide. _Can we do this safely?_ Yes, if it's up to him. His biggest reason for saying no just might be out of principle. He detests the idea of taking such full responsibility for another diver, but…

 _Fuck it._ John has always prided himself in being a stickler for safety, but if something he wanted as much as Sherlock wants this was within his grasp, would he bend the rules?

 _Yes, he would_. "Yes."

"Yes what?" Sherlock's head snaps up from inspecting his bare toes.

"I'll let you do this. But I will be watching over you, be with you every step of the way."

The relief on Sherlock's face — the gratitude and the overwhelmed relief— is a sight that John hopes he will never forget.  
  


_____________

"Forty-five minutes' bottom time. Maximum depth twenty."

"Ridiculous," Sherlock mutters, holding his hand gingerly still as John pricks his fingertip.

They're doing this on the dive deck, just before descending. John had insisted on doing a pre- and post-dive measurement himself; he trusts Sherlock to tell him the correct results — well, almost trusts him— so this is mostly to hammer home the point of how disapproving he still is of the man's decision to dive despite not fulfilling the medical criteria.

In thirty seconds, Sherlock is pressing a piece of toilet paper onto his finger, and John shows him the meter screen. "Six point five. Ask Mariza to give you some bread; we can go down once you've eaten it."

"Yes, Doctor." Sherlock gives him a slight smile.

For John it's odd, seeing him so accommodating. It makes him feel like he has power he doesn't really want.

_____________

The pile of wet planks on the sea bottom still doesn't look like much, but Sherlock's urgent excitement has kicked some life into the entire team. Once they'd descended, Sherlock had quickly decided that Morten's compass-reading was too slow, so he'd just darted off in the general direction with John in pursuit. Thankfully, the remains of what just might be Drake's ship aren't very far from their mooring.

Now, Sherlock is darting about the wreck site, instructing Morten and Joseph on where to take samples, what to sketch onto writing slates, what to measure and photograph. Anderson hadn't joined them on the dive, saying that whatever cinematic potential the spot had, he had exhausted it on their morning dive.

John follows Sherlock around, feeling not unlike a faithful hound, occasionally demanding an OK signal and for Sherlock to show him his hands. As long as they're steady and he's not getting cranky, John is willing to keep with their dive plan.

Ten minutes before the cut-off time John had set is up, Sherlock ascends a few metres shallower. John assumes he's done and wants to go up but instead the professor positions himself above the middle of the wreck debris field and stills his movements, hovering motionless above the ship ruin. He closes his eyes, the tiniest of frowns marking his concentration. His eyes begin shifting underneath his lids as though going through something in his head. When his eyes finally flash open, a wide grin spreads — one so unadulterated and joyful that it lights up his features. He spreads his arms like a soaring bird, breathes deep, releasing a heavy burst of bubbles, and seems to be just taking in the sight of the wreck below.

John can't remember seeing him this relaxed on a dive. He stays back but close enough that he can get to Sherlock with a few brisk fin kicks.

Sherlock glances at him, and John gives a nod as if to give him permission to enjoy himself, to take a moment just to take in every quivering breath of the cradle of life and death surrounding them in the ocean. Sherlock's shoulders relax as he surrenders to the water, and John wonders if he's imagining what the wooden carcass of a ship below them looked like riding on the waves high above, battling the treacherous waters.

 _He loves this_ , John thinks. _He loves this with a burning passion._

_Could he love a person with such devotion?_

_______________  
  


"This on?" John asks, tapping the small microphone clipped onto his collar.

This causes Anderson to tear his headphones off. "It's _on!_ Sheesh, I'd like to keep my eardrums."

"Sorry."

Anderson puts the headphones back on. "Need to adjust the volume, apparently," he mutters. "Ready."

Greg nods to John. "Just say what you told me yesterday. About why you do the work you do."

John gives him a crooked grin. "I shouldn't be taking requests from you after the stunt you pulled yesterday," he teases. He'd woken up from a long, post-dive afternoon nap in the sun in just his swimming trunks to discover that Greg had written 'cock' on his chest with sunscreen. The word now remained there, lighter than the surrounding, reddishly sunburnt skin.

Sherlock, walking by as John had tried to swat the idiot with his damp towel, had called them _children_.

"We're rolling," Anderson reminds him in a nasal, sing-song voice.

John shifts in his seat and looks past the two men out across the open ocean. "If you have to ask why people base jump or climb mountains or cave dive, you're not going to understand the answer. At one point, you realise you can stop explaining it to people, that you don't feel the need for acceptance again. You say look, this is my life, and I need to live it the way I want, to chase that passion and leave behind those things that drag me down."

"Do you think the expedition has been a success?" Greg asks.

"Depends on what you mean by that word. We all got back alive and sane and healthy so, yeah. You'd have to ask Prof–– _the research team—_ about what they think we achieved in terms of archaeology, but we certainly did scout out some gorgeous wrecks."

Sherlock had granted Greg another interview in the wake of their dive, and John had listened in. Eyes bright and so excited he could barely sit still in the chair Anderson had set up on the top deck, Sherlock had delivered a frantic mini-lecture of Sir Francis Drake and then walked the viewers through Anderson's footage of the wreck site. Through his words, the bits of wood and rubble had come alive. They had shed the grime and damage from being buried on the sea bottom for centuries and risen back onto the churning cauldron of a stormy sea, with the crew battling the waves and trying to save themselves in these alien lands. Delivered in Sherlock's deep, rumbling, rich-as-dark-chocolate baritone, John had to agree his narration could be an asset for documentaries such as this.

"What's next for you, then?" Anderson asks, adjusting the zoom.

"Back to Malta. Home." A part of John still startles at the word. _England is... home, isn't it? Always will be? But isn't home also what we choose?_ Maybe the whole world is his home, now. At least much more so than when he was just a kid living in a tiny house in a suburb. Trapped. Horizonless.

_Is that how Sherlock has felt for a long time, now, with that prize arsehole he's dating-and-not-dating?_

The expedition is over. They'll step ashore tomorrow. Fly each to their next destinations. Scatter to the winds.

_James Moriarty is not my problem. Not much more I can do than what I have said to Sherlock, is there?_

He clears his throat. "Yeah, um, I'm just going to wait for that next interesting phone call, you know?" Greg and Anderson both nod. "I've been in talks about some work in the Philippines, so maybe that'll turn into an actual engagement. Just… it's nice not to have a plan right now. Never liked those. Hated the idea of applying for medical speciality training; looking at the next six-or-so years ahead with little control over where and how I was going to live."

But what, exactly, is he doing with all of his purported freedom these days?

He'll fly to Malta, go back to his flat, dive, spend his evenings in Paceville's bars and clubs, looking for the next warm body to kick out of bed before stumbling to the shower to wash away the forensic evidence of that evening's carefree conquest?

Why does he suddenly feel so bitterly sad to leave this group, to go back to being the lone wolf he has always joked about? Why does the thought of the latest male and female offerings of the British tourism industry on Malta not entice him like they used to?

He'll never grow tired of diving. But, could he grow tired of the lifestyle he has thought of as part and parcel with it? This is just _his_ version of it, this nomadic existence. It's his choice to let nobody stay the night. _Plenty of dive pros have partners and families._ He's always looked down at them, a bit, as though they were wasting an opportunity. _What if they enjoyed that opportunity, after all, but nobody wants to live like that forever?_

"Would you consider returning here on another expedition?" Greg asks.

"I don't know. There's no proper bar, is there, except for that self-serve upstairs with those bleach cheap Chilean wines and that local piss Morten drinks insisting that it's beer, so it's a very bootstrap operation," John jokes, making Greg chuckle.

"Do you have a favourite moment from this expedition?"

John scrambles to come up with something suitable for a BBC nature documentary. The first image that comes to mind is Sherlock from only a few hours earlier, hovering motionlessly above the wreck in the ash-blue darkness of the ocean, looking like some exotic creature of the sea or a ghost of a sailor guarding their final resting place.

He voices none of it because somehow, that moment had felt as private as it felt sacred. _You can film this stuff, and you can try to explain it to people but being there… it's so different._

On a wreck dive, there's the marine environment, but there's also so much more — the human impact that connects an explorer to what is being explored. The rich history, the lives lost, the poignant reminders of how small, weak and insignificant we all are in the vastness of the water. Human history is a history of waterways, wells, journeys, warfare at sea and discovery of new lands after sailing for months.

"Just being out there, seeing things no one has seen before," John decides to say, but instead of sounding proud he ends up sounding unsure because this idea suddenly reminds him of the day that he — _we_ , he corrects to himself — nearly lost Sherlock. The day he witnessed the cracking of that carefully constructed facade when the stress and fear and trauma tore it all down. _Don't let the Centre be the ship you go down with_ , John pleads in his head. _All these people at the bottom of the sea in the wrecks we've dived, they were scared, too when the storm hit, but unlike them, you can still escape with your life._

"One hell of an experience," Greg summarises, causing John's chain of thought to break like a wave hitting a breakwater.

"Yeah, though you didn't even dive any of it," John can't resist teasing.

  
____________________

It's the final night of the expedition, and nearly all on board are celebrating with the last of the beer and wine. John would have expected to want to join in, but for a reason that eludes him, he doesn't feel like company tonight. He takes a whisky offered by the captain to the small front deck close to the command bridge — the cockpit where he'd once watched over a napping Sherlock.

They're on the move, have been so for six hours now towards the mainland. They will arrive in port in the early hours of the morning.

John turns his head to look back towards the Entierros, now no more than dark blotches on the horizon. It's strange, knowing he may not ever return to this place. Usually, he likes adding feathers to his proverbial hat and would be already anticipating his next adventure or looking forward to returning home, but something about this journey has been different. Important. Sobering. _It won't change anything concrete, of course_ , he tells himself. He'll return home to Malta, continue work wherever and whenever an interesting assignment pops up.

He sighs, staring into the amber liquid he's swishing in his tumbler. Maybe he's just tired. Maybe he needs a break, to take a few weeks to recover his taste for it all. He shakes his head and sips the whisky, watching moonlight rippling in the surface of the quiet sea and the white spindrift being spat out from underneath the hull as the boat moves towards its destination.

He absent-mindedly leans over the railing to look onto the larger, lower front deck when a light there catches his eye.

It's a laptop screen. Sherlock is there, typing away furiously, maps and notes spread around him. John has no idea how he can even see the text on them in the dim light. He clears his throat, and when Sherlock looks up, he raises his glass, aware that the better light in the cockpit will show who he is and what he's doing.

At that moment, the sound of Greg karaoke-belting out Heart's Alone in the bar lounge above starts polluting the waters. John cracks into a laugh and rolls his eyes.

Sherlock watches him for a moment, says nothing. Then, he closes his laptop lid and disappears down a side corridor.

John curses. He hadn't meant to break the man's concentration. Sherlock must be excited to get to draw together everything they've discovered on this trip and plan how to publish his findings. Academia has never interested John, but he knows from observing his fellow doctors' lives how much work getting anything published is. It's the excitement that seems to make it possible to endure such bureaucracy: the passion, the enthusiasm, whatever one might call it. It sparkles to life in Sherlock so very easily when he feels safe to express it. In Oxford, it must be constantly side-lined, buried and extinguished by all the bad things going on in his life. Things which he doesn't seem to be able to discuss with anyone.

Expected solitude for the rest of his drink, John is startled when footsteps sound from behind him.

Sherlock appears, a can of beer — of all things — in hand.

He's holding it with his fingertips, frowning when he sees John's eyes lock on it. "Lestrade insisted I should have this though I have no use for it."

"I'll swap?" John still has half his generous whisky portion left.

"Is that from the Macallan bottle I spotted in Jose-Perry's stash?"

"Could be."

"Acceptable," Sherlock announces. He gives John the can, receives the tumbler and descends gracefully onto a deck chair.

They sip their drinks in silence, one that stretches for so long that John wonders why Sherlock had joined him.

"Flying home tomorrow, then?" John finally asks, after cursing that he'd be the one to crack first. By the time they pull into port, no one in the team has dived in 24 hours, so there's no need for a safety margin before air travel.

"Mm." Sherlock doesn't turn to look at him.

"It's been…" John starts, suddenly realising any summary of the trip would require a lengthy explanation, "…quite something." He tries to coax some perkiness into his tone, but he feels boneless from the alcohol and a bit adrift with the things going through his head, so the attempt falls a bit flat.

Sherlock inhales, then breathes out quickly as though a thought has caught him unawares. "He's there, at home. Waiting for me."

Unsurprisingly, it doesn't sound like the dreamy anticipation of being reunited with a lover.

"You have to do something about that," John says quietly, raising the beer can to his lips as a shield between them. It's not his place to offer advice, but he doesn't like to see someone trapped in an obviously bad place; who would? It's a tug-of-war in him, now — stay silent and enjoy the moment and perhaps wonder later if he should have done more or spoken his mind and hope that his words won't offend or repel.

He remembers the scars he'd seen, felt with his fingers. _The bastard marked him, and how he's practically stalking him._

He'd felt oddly protective of Sherlock even before he'd learned this reason for the man's aloofness, for his hiding away from even the academic world. _Why?_

"James is not a man to whom one says no."

"You can't hide forever. You can't just go from one expedition to another." It's not a question, and Sherlock gives him no answer. "If anyone can teach him the lesson that he doesn't own you, it's you."

John should leave it at that, but there's a sudden compulsion to do what he can because he suspects he's the only one Sherlock allows to know how he feels. Not that John knows much about his life: he could have relatives or friends to see him through this.

Yet somehow, John really, really doubts that.

"This guy is not the only option in the world. It's not your job to keep the institute alive. Surely, you're more useful to them than some one-in-a-dozen millionaire."

"Not all millionaires are queueing up to fund historical research."

"Just don't sacrifice yourself for your work. You're not married to it."

"That's precisely what I thought I was — until James argued that _a romantic entanglement with the right person would complete me as a person and teach me to change._ He worked hard to prove that with him, such an entanglement could be tailored to fit my work."

"That's why he treats you so badly — because you're such a _perfect fucking fit_?" John crunches the now empty beer can and drops it into the bin in the corner.

He expects Sherlock to get angry, but instead, he just continues looking out across the black surface of the sea below. "When you've never been the person anyone would ever pick … When someone finally does choose you, you think: this is it. I have to overlook some things and make this work."

"Not what he did to you. Not that," John says sternly. His hand hovers in mid-air for a moment, instinct telling him to reach out, to place his palm on a bony shoulder, but he can tell Sherlock is battling the impulse to go, to shut him out. John lets his hand fall, gives him space.

Sherlock lets out a self-deprecating scoff, carefully avoiding looking at him. "I miss him sometimes. Perhaps not him, but someone… Being there." The admission is strained, tentative, as though testing the boundaries of what is acceptable.

"Of course, you would. Even when a relationship is utter crap, there's still the stuff you liked about that person, the stuff you didn't want to lose."

"Sometimes, I wonder what those things even were. Or, if I merely accepted a union of convenience and tried to put up with expected aspects of it which I wasn't aware would be so…"

"…Not you?" John suggests.

Sherlock gives him a fleeting glance, lip quirked up. "Couldn't have said it better. It's hard not to blame myself; it was a tug-and-pull of a beginning. I have asked myself many times if I could have fought harder, if I should have been smart enough to listen to the voice at the back of my head?"

There's a loud, drunken bout of laughter from the aft of the boat, and someone starts singing _Hot Stuff_. An errant memory floats into John's consciousness of a night out in Sicily which had ended with an escape through the window when the husband of _Annabella? Chiara? Alessia?_ had come home in the middle of a very nice blowjob. That song had been playing on the radio earlier that night when they'd danced. _Why do I remember that stupid detail, but not her name?_

"Shouldn't you be back there?" Sherlock asks, his bitter tone implicating that he doesn't think he would be welcome to do the same. "To keep Lestrade from falling overboard."

"I'm fine right where I am, thanks," John says softly.

With Sherlock, he finds it challenging to find the right words, to pick the right thing to do. None of his time-tested patterns work with the man, so he has to improvise. It's frightening and exhilarating in equal measure, and that combination is dizzying and intoxicating in a way John hasn't felt in years. He feels like a schoolboy again, fumbling for the first time to make contact with someone he likes. There is no clear goal in sight; he's not trying to put on his usual moves to bring someone home. The slate is clean; he can experiment. _Explore the unknown_. Sherlock's words on that first night had pierced right through his act and called him out. _Some of it was rather mean_.

A suggestion takes form in John's head the likes of which he's never made. Everything, every little thing, takes on more meaning when the end game isn't an orgasm. _Everything is different with Sherlock_.

The moment feels terribly fragile.

John forms the words, braces himself to accept whatever consequences they may have.

"Come spend the night with me," he says.

The moment breaks: Sherlock slams down his glass on the table.

"So, you haven't understood a single word I've told you about myself? After _everything_ , this is all that's in your head? I must salute you for playing the long game; I really must; spending weeks trying to snake yourself into my good books so that you could have a rematch of that asinine bar counter attempt to–––"

John steps closer and presses a palm on Sherlock's mouth. Sherlock's eyes go wide, then narrow with rage.

"I _have_ been listening, and that's why I'm asking," John tells him. "Spend the night with me, in my cabin. Not for sex, but for company, because I doubt you want to be alone right now when you're so painfully aware of what's waiting for you at home. I'm proposing whatever you want or don't want. I'm not defining it in any way, and it doesn't have to mean anything."

He lets his hand fall. This whole exchange has made him realise how laden with expectation certain innocent expressions have become. For the majority of the world's population, _spending a night together_ means sex. Now John Watson, a man to whom that phrase has always meant precisely that, is trying to use it to suggest something completely different. He, who has already once propositioned Sherlock for sex in no uncertain terms. But… how else was he supposed to phrase his suggestion, then? Anything he might have said would have sounded the same against the backdrop of their awkward first meeting.

Sherlock looks confused and dismissive. Hurt, even. "Why do you think it wouldn't mean anything?"

John cards a hand through his salt-coarse hair. "I––"

"Does it automatically mean _nothing_ if genitals are uninvolved?"

"No, that's not––"

"Are you extending this invitation out of pity?" Sherlock is biting his lower lip. "If yes, then I detest it."

"No. Neither of us feels like joining those idiots back there, and maybe _I_ didn't feel like just going to my cabin alone, packing and then preparing for a long flight back in coach class. Maybe I wanted to do something nice tonight. I thought that maybe you wanted company. That maybe you missed him and hated missing him. That maybe you felt like not being alone."

 _I'm asking because I want your company. I want anything you're willing to give me._ God, why's that so much harder than telling someone he wants to stick his dick in? Why would he be this nervous? _It's not like we're likely to see each other again. This isn't some pointless ships-meeting-in-the-night cliché_ , John admits to himself. _This is… us._

Sherlock doesn't seem to know what to do with his outburst.

A cloud covers the Moon, and for a moment, it's hard to make out his expression.

"I'd like that," he finally says.

John knows he should be content with this tentative yes, but there's something that's been burning at the tip of his tongue ever since he found out about Sherlock's secrets. He's said it once, twice, but it feels like the most important thing to make the man understand. "You know he's not the only option, right? Leaving aside all the worry about financing the Centre, you can do better. You deserve better," John states plainly.

"Is this the part where you tell me that there are plenty of other fish in the sea?" Sherlock asked, waving a hand at the ocean stretching out to the horizon.

John stares at him for a minute before the other man's lip quirks slightly, a mischievous glint in his eye. Then, they both break into giggles. "Oh, God. That was horrible," John cackles.

"It was, wasn't it?" Sherlock agrees. "As pickup lines go, I think we're even."

"That doesn't even deserve to be called a pickup line. Doesn't mean it isn't true, though," John points out once he gets his laughter under control.

"I know that, John. I do. But my chances of finding a partner are slim even before I explain to any candidates that I don't want to engage in intercourse."

"What makes you say that? Why are you so sure? I assume you're not some serial dater who'd have a big data set to lean on."

"I've been told I'm... odd. Prickly. That I am too hyper-focused on my work and don't value other people. I can't be bothered with politeness — it's nothing more than a mask for lies. I play the violin when I'm thinking, regardless of whether it's day or night when or if the other person is trying to sleep. Sometimes I don't talk for days on end or only talk about work. I'm... hardly an ideal companion."

"I'm going to guess who it was that told you that nonsense. Classic abusive arsehole manoeuvre, by the way: convince someone that they're unlovable, that you're lucky they're giving you the time of day. That's how they make you afraid to leave. Bollocks."

"He's not the only one to have said it."

"Still bollocks," John insisted. "You're intelligent and interesting and funny. Too clever not to be able to make some domestic adjustments for someone you fancy. You're passionate about your work. Dedicated. That's sexy. And you play the violin? That just means you're even more brilliant, Sherlock. Don't let him, or anyone else, tell you otherwise."

"Are you trying to sweet-talk me into your cabin, John Watson?"

"Nope. I'm just saying that what you think is a roadblock might just be a speed bump for some prospective partners."

"What does that even mean?"

John paused. _Alright, it was a pretty shit analogy, plus Sherlock obviously has little skill in deciphering metaphors._

He tries another tack. "Look. I like sex. A lot. I find it pleasurable, and I enjoy giving my partner pleasure in return. I wouldn't enjoy it if the other person didn't want it. I would adjust and make that sacrifice if I loved them enough. That's the kind of compromises you make in a relationship instead of forcing yourself to leave your comfort zone." _Five Oceans Watson giving relationship advice. Christ._ "I propositioned you at the resort because I liked what I saw. And getting to know you hasn't put me off — quite the opposite. That's… that's how it works when…" John snaps his mouth shut. He's said too much.

Sherlock's reply is a thoughtful hum.

  
_________________

  
Once they're in his cabin, John strips down to a T-shirt and boxers, shoves some of his clutter underneath the bed and makes sure the sheets are presentable. If it's sleeping together they'll really be doing then John wants to be prepared.

Sherlock appears five minutes later, wearing black pyjama bottoms and a long-sleeved burgundy T-shirt. He is carrying his laptop and a bottle of water.

"Mind if I work? Might help me sleep." He glances pointedly at the bed.

John smiles. "No, go ahead."

Sherlock takes over his desk while John grabs a spy novel he'd borrowed from Terry and burrows under the thin blanket and sheet. The air-conditioning is effective, and he likes sleeping with more than just a sheet. At some point, he dozes off to the ambient cacophony of the engine and the waves and Sherlock's typing and shuffling of papers.

At some point, John stirs half-away as the mattress dips. He doesn't reach out, doesn't say anything, but can't help but smile when he can sense a warm but tense body beside him. _Did he crawl in with me because he thought I expected it, or did he do it because it was what he wanted?_

_____________

In the morning, John feels the most refreshed he's felt on the whole trip. He twists his torso so he could turn towards the middle of the bed and say good morning, but when he opens his mouth, the words never come — he's alone.

The sheets on the other side of the bed are already cooling.

John can hear the sounds of a port just outside the walls of his cabin, and the boat is no longer rocking with the waves.

An odd, aimless regret sets in as he surveys his still-unpacked clothes and diving gear. After pulling on the first bits of decent clothing he can find, he wanders out to the aft deck.

Jose-Perry is there, overseeing the emptying of the septic tank. "Morning, John."

"I see we've arrived. Anybody else still on board?"

"Most of camera crew leave for airport five minutes ago; you just miss them. Staff still here, we need to fix boat for divers."

"Right. I'll start packing and get out of your hair."

"No hurry."

John's flight isn't until six in the evening. He starts heading back to his cabin, but after a few steps, he can't resist turning back to face the captain again. "Is Professor Holmes still here?"

"Professor leave four hours ago."

"Right, yeah, of course," John stammers. _Wasn't their flight at four? If some of the camera crew are still here, where's Sherlock gone?_

"Did he leave alone, or…?"

"Black car come pick him up for private plane. He was surprised," Jose-Perry says with a shrug.

A chill crawls down John's spine and ties a knot in his stomach. _Surprised by boyfriend dearest?_

After aimless, anxious wandering around the boat, John ends up in the downstairs salon. Blue O Two brochures have been arranged onto the table; there will be a liveaboard departure that evening once the research team is gone.

_This is it, then. It's over._

He digs out his phone. There's now good WiFi since the marina network extends to moored vessels.

A search on Youtube under Sherlock's name produces a lecture from a few years' back at an open day of the Centre. Sherlock looks every bit himself, but the worry lines now etching shadows onto his features aren't there. He looks younger, more boyish, nearly vibrating with excitement as he answers questions from people lined up to attend the lecture. His smile is careful, and he speaks fast; John can't hear what is being said because the microphone isn't on; this is just B-roll as the opening credits are shown.

When the programme starts proper, the camera cuts to Sherlock standing on a conference podium.

"Marine archaeology," he starts, his words sharp and keen, "is the study of human interaction with bodies of water by studying associated physical remains. Not only do they tell us about the everyday life of humans past, but they can also act as windows to historical criminology, religion and war strategy. Also known as maritime archaeology, this field of archaeology can be exercised as a dry land discipline, with artefacts raised from the depths and ships brought up from where they lie on the sea bottom. However, many researchers, such as myself, believe that removing historical items and vessels from where they have gone down decimates a lot of crucial evidence. So, it appears pertinent to record that data before any salvage operations are made. This can be done through what we call underwater archaeology. That can entail both scuba diving and remotely controlled robotics…"

John has stopped listening. Instead, he just watches as emotions shift on Sherlock's features, feelings much less hidden away than he's seen in the past month. _This is the real Professor Holmes_. The heart-breaking evidence of how much the relationship with Moriarty has robbed him of is painful to watch.

 _Don't let him take it all away from you. Please, Sherlock, don't let him win_.

  
  


**Notes for the Chapter:**

> After diving, one must wait before flying. Remember that nitrogen which dissolves into a diver's tissues? Well, if you hop on a plane, it just might bubble up as the ambient pressure changes. It's fine to dive immediately after flying but not vice versa.
> 
> The unearthing of Tutankhamun's tomb in Thebes, Egypt was largely funded by the Earl of Carnarvon. Many of you would recognise the grand house in which even the modern-day Lord and Lady bearing that name inhabit from photos — it's Highclere Castle, also known as Downton Abbey.


	13. Cast Adrift

> **From:** john_h_watson56@gmail.com **  
> To:** sherlock.holmes@arch.ox.ac.uk  
>  **Subject:** Take care
> 
> Hi Sherlock –
> 
> I hope this reaches you, found your address on the Centre website and guatemala airport's got some work to do on their dodgy wifi. I've attached two contact cards one's for greg like I promised and i just realised I had the info for one of my medschool mates who's a private sector endo diabetes specialist now. He could help you sort out things so you could dive. Not tec but anyway. Sorry we didn't get to say goodbye. Look after yourself.
> 
> – John

**  
  
— One month later —**

**— Michelangelo Gay Club, Paceville, Malta —**

Roberto is tall, perfectly tailored and has slightly curly, dark hair. He's the nicest thing John has seen this evening and should provide a perfect hop back in the saddle after the Guatemalan abstinence — save for John's own hand, of course. Lucky for him, the night is still young, so the bloke had not been snatched up by anybody else.

Roberto has just told him that the friend he's travelling with had got terribly sunburnt and is sleeping off a headache in their hotel.

"Just a friend, then?" John asks pointedly, casting a long look into Roberto's brown eyes over the rim of his whisky tumbler.

A wide smile blooms on the Italian's features. "Yeah, just a friend. I'm not currently seeing anyone." He shrugs. "I'm not looking for anything serious."

John is certain there's a suggestion there, in his tone. _Not seeing anyone and not looking for anything permanent_. He knows this game; Roberto knows this game.

 _And that's what it is — a pointless game_ , complains a bitter baritone somewhere in the deeper recesses of John's head.

"Why Malta, then?" He asks, leaning his elbow on the counter but taking care not to let his posture slump. He would have expected to be a bit rusty slipping into this role but so far, so good. Maybe, once he gets things moved into the bedroom, it'll feel like slipping on a comfortable pair of trousers. Or taking them off.

 _Too comfortable?_ Something about the bourgeois ease of it is suddenly grating on John.

 _How many more notches do you need on your bedpost? You think that'll make any of them mean something?_ Mocks that sweet-and-sour baritone once again.

 _Shut up_ , John tells himself.

"Close to Sicily; we took the ferry over," Roberto answers, frowning a bit which makes John wonder if there's something wonky going on with his expression.

"Nightlife better here, then?" He suggests, swirling his whisky and tilting his head just so, luxuriating in the sight of Roberto leaning closer. He can smell a bit of aftershave and heat-kissed skin still carrying traces of sunscreen.

"By a mile." Roberto is smiling at John: it's an open, unadulterated and inviting smile, and his body language is definitely saying _yes_. He's turned to face him fully, his knees have fallen open a little, and the initially appraising looks have turned into something a bit more indulgent, more languid. Neither of them is drunk, just pleasantly buzzed.

"You here for a holiday, too?" Roberto asks.

John is suddenly irritated. _Sherlock could instantly tell I'm not._ He blinks, surprised at his own reaction. Why would he want to be deduced, have his emotions stripped to the bone? He wants control over who he is tonight and what he wants and how much he gives of himself. It's not usual for him to have to work very hard to get past the point of getting acquainted. People like him. He's easy to get along with when he turns on the charm. But they don't get any closer than he lets them.

 _This is nice_ , he reminds himself. _Roberto is nice and fit and God, do I want to get my hands on that arse._

Someone bumps into his potential date, almost spills a bit of their cocktail on him. Apologetic, lingering smiles are flashed, and the other man opens their mouth to say something, but Roberto instantly settles back towards John, looking expectant.

Both their second drinks are now finished. _Now or never._

John knows he's got this. _Hook, line and sinker_. This could be a really great night.

Yet, something makes him hesitate. He feels… bare. Stale. _How many more nights like this will I have? How many are enough before I might want something else?_

He tilts his empty glass in his hands, feelings Roberto's eyes on him, painfully aware how the seconds tick past. _This is not an addiction_ , he insists to himself. _I've just never known what else to do, how else to protect myself._

He had thought he had the perfect armour. He thought he was keeping his defences intact while trying to break through Sherlock's. Yet somehow, the man has stripped him of his own, instead.

John feels like he's standing on the battlefield realising he's forgot his lance at home.

"So…" Roberto starts, "My hotel's just there on the waterfront."

 _It's likely the Westin Dragonara, then_. A very nice place. A tumble in such high thread-count sheets would be a nice change to John's barebones apartment with its Ikea sheets.

_What if… it doesn't have to be a battle? What if it was like coming home, instead?_

He can't fuck Robert and keep thinking about Sherlock, can he? Roberto wouldn't ever now, but it feels so disingenuous.

He's on his feet by the barstool before he's even made a conscious decision. "Sorry, got to head home. It was nice meeting you; enjoy your holiday."

 _I sound like a fucking tourist rep_.

It's a walk of shame to the door and back to his apartment in the neighbouring St Julian's area. On the other hand, John doubts that walking home in the early hours of the morning smelling of Roberto's sweat and aftershave would have felt any better.

For the first time in years, Malta doesn't feel like home.  
  


_________________

"You free tomorrow?" Morgan Baron, the owner of Scuba Barons on Gozo, asks John on the phone.

"Yeah. What have you got?" Morgan, a fellow British expat who has been running a very reputable diving centre in Marsalforn for years, is one of the only employers for which John is willing to bother driving around Gozo. The smaller Maltese island's narrow, steep streets are a nightmare.

"Guided dive at the Blue Hole," Morgan declares.

"Nothing in Dwejra requires tec gear. Why would you need me for that?" Morgan always has a full roster of divemasters and instructors for the summer season, and if one of them was sick and he needed a temp for a guided fun dive at a popular recreational site in on the Gozo coast, John would not be the first on the list. He doubts he'd be the tenth.

"You were specifically requested for a one-on-one."

"Oh. Must be someone I've dived with before, then. Probably on hols here and wanting to do something light. Okay." Dwejra has a semi-decent road leading down to the Blue Hole, a popular snorkelling and swimming spot that's the entry point of a reef dive with some interesting underwater topography.

"I know you hate the van, so I'll give you Nick's truck."

"Perfect. Single tanks, no blend?"

"Nitrox was requested."

"That works for me." It'll be more like being on holiday than working, this dive. Since the client wants Nitrox, they must be a certified diver beyond the beginner level, and the site is a nice one.

"Client's staying at the Kempinski; could you pick him up on the way? He says he's brought all the other gear he needs besides tanks, and he's already submitted all the requisite paperwork via email."

"Sure. I'll pick up the tanks at nine."

  
__________________

  
The next morning, John shrugs into PADI's Malta version of the Rec Tec Instructor polo and pairs it with dark blue shorts with Speedos underneath. He had stopped bothering long ago to wear the official staff T-shirt of whatever diving centre he is working for on a given day since so many different ones employ him on a freelance basis. He looks tidy enough now but, by the end of the day, he'll have to chuck all of it into the wash; there's a very specific and foul smell which diving truck exhaust fumes, sea gunk, human-marinated neoprene and sweat merges into.

The valet at the Kempinski hotel, one of the fanciest on Gozo, frowns at the banged-up truck John arrives in, but it's hardly the first time a dive company comes to pick clients up in vehicles which have born the brunt of Malta's insane driving culture. Only a certifiable person would buy a new car to drive around Gozo.

John strides into the wonderfully air-conditioned reception and sits down at the edge of a fountain there. It's five minutes before nine-thirty, which is the time Morgan had given to the client. John spots a Mares equipment bag sitting by the reception counter which likely belongs to his client whose name Morgan had mentioned but John hadn't really heard it over the racket of the air compressor; Morgan must have been using the landline at the back of his shop. John doesn't bother to check the nametag of the new-looking bag; he won't remember the client's name after today there's no reason to bother making an effort.

Or, so he thinks.

The door to the gents opens, and out walks _Sherlock_.

_The guided dive client is–––_

Sherlock strides up to him. "Morning, John."

"What––"

"I thought I might give you another chance to explain–– I mean—no, to show me—why you make such a fuss about the alleged _fun_ of your trade."

"I thought I told you that you shouldn't dive until you got your hypo awareness back," John manages to parse together.

His eyes roam over the sight of Sherlock. He takes in the slightly swollen lower lip, the healed cut on a cheekbone, the bruise on a forearm. _Please tell me you're no longer with him_ , he wants to say, but the evidence speaks to the contrary. But, John can hardly ask about any of that right now in the sunlit, busy foyer of the hotel. "But Morgan said you emailed him all the necessary paperwork."

"What Mister Baron received was a somewhat embellished version." Sherlock digs out a piece of paper from his pocket. "Yes, I am well aware of the one-year rule, but I was hoping you would be willing to bend it for me just once more. I've brought a statement from the endocrinologist to whom you were kind enough to direct me; he's been helpful. And, I have this, now; a brand-new model cleared for diving down to thirty metres," he announces proudly and pushes up the sleeve of his shirt to reveal the tell-tale bump of a subcutaneous glucose sensor. "It has dive computer integration. An experimental model a contact of my brother's has been developing with British special forces."

John whistles. "I had no idea there are so many diving diabetics in the army."

"There aren't; pressure-proof glucose remote sensoring is not their endgame, the monitoring of other human biochemical parameters is, but they are using existing systems as a canary in a mine."

John decides he does _not_ like that analogy. Instead of relying on experimental technology, Sherlock should be refraining from diving until his diabetes is better-controlled.

"Professional divers are getting more obese just as everyone else, and for long stints underwater they may need a solution to monitor their levels even if they've just got type two," Sherlock argues. "Satisfactory for a fifty-minute dip just off the coast?"

"It adds one more thing to monitor. More data means more distractions and more things to sift through when making decisions."

"I haven't dived since the Entierros, and I don't intend to dive with anyone but you before I have this issue under control."

John exhales, shakes his head. Henever has trouble saying no to other divers. _Why does he find it so hard to_ _say no to Sherlock?_

"As long as I stick to what you dully described as 'recreational limits', I think I can manage since there will be no complex gas management," Sherlock pleads. "Please, Mister Watson, I've come all the way here just to see the Blue Hole," he jokes in a singsong voice. "I'll trust you to look after me, _Doctor_."

John can't help but chuckle, then waggles his forefinger at Sherlock with a scowl ruined by the grin he's unable to contain. "Apparently you've forgot one sacred safety rule: no trust-me-dives beyond your abilities."

His expression then sobers up. "You sounded frightfully close to some of the beginners who keep popping up at the local diving schools wanting to dive the Hole; it's too deep for them and requires some actual buoyancy skills if you don't want to get stuck under the arc."

"The Blue Hole is lauded as one of the finest recreational dive sites in the world, so it must be some kind of a demonstrative standard. So, show me," Sherlock prompts again.

"Um–– alright. On your head, be it," John relents. _Fuck_. _It really is on my head, of course, if something happens, but I just…_

After coming home, John hasn't wanted anything as much as he wants to say yes right now so he can dive with the man who's haunted his thoughts too intensely for too long.

  
_________________  
  
  


The drive to Dwejra goes quietly except for the road rage which invariably takes hold of John whenever he has to navigate Gozitan traffic. "Some of these old fuckers think they should always use whatever lane's in the shade, never mind if there's oncoming traffic."

Sherlock doesn't respond. He keeps stealing glances at John, and something about his silence seems to speak volumes. But speak of what, John is unsure. _Why is this happening? Did he leave James Moriarty? Did he resign from the Centre? Why is he here?_

John parks in the tourist lot close to the cliff edge, where beachwear salesmen and souvenir kiosks have already opened for the day and a local is busking with an accordion.

Sherlock rolls his eyes at the sight and starts pulling his kit off the back of the truck, but John stops him and locks up the truck. "Let's walk to the site first; I'll give you a briefing."

"I've studied the site maps and guidebooks," Sherlock dismisses.

"I'm your divemaster today, so I will bloody well give you a proper briefing," John insists with a crooked grin. "We're also a _buddy_ team today," he adds, aware of how Sherlock loathes the vocabulary PADI has adopted to make diving sound fun and friendly.

Sherlock worries his lip with a shake of his head. "Lead the way."

They walk the smooth limestone paths to the edge of the cliff overlooking the Blue Hole, and the view that opens up is a spectacular sight. Edged in lighter blue where the coral grows, it's a circular opening in the limestone at the edge of the sea, the middle of it plummeting down to fifteen metres and looking inky black and blue from up high. Bubbles from divers' regulators are trailing up to the surface among swimmers and snorkellers.

"The entry and exit point's the Hole itself. It's a nice and easy descent, just mind the cliff-jumpers. Arch is at six metres; from there, we descend down to eighteen and make our way to where the stone arch that collapsed used to be. It now looks like a mountain underwater; you'll like it," John adds to counter Sherlock's sceptical expression. He does seem impressed by the view.

"Fish like can be scarce at the beginning of the dive, but things get richer in the boulder field. At the end of the dive, we can go up a chimney into what is called the coral gardens, where there's plenty of life. The chimney ascends from twelve metres to six so don't forget to remove a bit of air from your BCD as you ascend," John adds as though lecturing a group of beginner open water divers.

"I'm sure you'll rescue me if I forget," Sherlock replies with a smirk.

Neither of them will probably even use a regular BCD today; John always uses his wing, and he would wager a guess Sherlock has a similar one since he mostly only tech dives. _Then again, his equipment bag looked new. Maybe he's bought regular scuba gear since he's unlikely to be ever cleared for tec again. But why would he buy scuba gear if he loathes fun diving?_

They head back to the car and Sherlock starts lifting their tanks out while John puts his big plastic gear crate on the ground.

"Ready to be my buddy, then?" John asks, lifting down their tanks from the back of the truck.

They both know he's not just talking about this dive.

"We'll start there and see how it goes."  
  


______________  
  


The Blue Hole never disappoints. Once they sink beneath the surface, leaving behind the hordes of sunbathing tourists, the arch connecting the sinkhole to the open sea comes into view, shining an alien blue light from the open ocean. This is what has made Maltese diving famous: the colours of the sea combine with the strange geological formations of the local limestone to create underwater landscapes unlike anywhere else.

After exploring the fringe reef, John kicks towards a pinnacle formed by the collapsed stone arch of what used to be known as the Azure Window. The pieces of it are quite bright white since coral and sea muck haven't yet covered them. Between the mountain-shaped rock and the coastal wall, John spreads his arms, signals Sherlock to do the same. They turn to face the open sea and then close their eyes. There's no current, and their skill level ensures perfect buoyancy; they are suspended in midwater, flying without moving in the vastness of the sea. When neither is breathing out, it's quiet except for the faint whoosh of the waves high above and the rumble of the countless creatures in the sea. When John opens his eyes again, he sees the seawater below his ripple with a warmer inflow of water; they're right above a thermocline.

He asks Sherlock how much gas he's got and whether he's cold by rubbing his hands along his arms. His answer is a shake of a head and three gestures masking 140 bars. Thanks to Nitrox and both of them being economical gas users, they can make this a long dive ending with an exploration of the rock labyrinth of the coral gardens.

_______________

  
The walk back to the parking lot feels longer now that there is less to look forward to. Getting out of the Hole requires wading around in a slippery tide pool, then clambering on sharp rocks and finally drudging up steps cut into the cliffs and then a few ladders. It's just two hundred metres, but in the scorching heat with all their gear on, it's heavy exercise.

"Best be slow and safe than fall on one's arse", John tells his diving partner, "it's happened to me a couple of times here. I've seen divers crack their heads open when they've taken a tumble on the stone steps and fallen between the boulders."

Sherlock says little as they put away their gear.

In the car, after John turns on the engine and puts it on reverse, he finally gives his judgement on the dive: "That was _amazing_."

John melts into a smile as he shoves the stick onto the first gear. "I'm glad you liked it. It's one of my favourites, rightfully belonging to all those top 10 lists. Admit it; it was kind of magical, wasn't it?"

"You romanticise things like a bad novelist."

"Your secret's safe with me. Lord forbid anyone finds out you know how to have fun."

"The scenery was satisfactory, yes, but it was… I have never quite enjoyed the diving itself like that. It's always served a purpose; I've thought of it as a sort of a commute to archaeological and historical discoveries. A necessary evil."

John narrowly dodges an incoming tour bus as he heads up the hill. "I meant to ask you in Guatemala, but forgot in all the commotion on the boat, what you meant when you said that you somehow force yourself not to get scared doing it? How does that even work, and don't you think fear is sometimes a bit useful?"

"I treat the risks as a problem to be solved. I don't dwell on them. If I did, I doubt I'd dive at all."

"Well, it's always a careful balance, and you have to make your peace with it. Statistically, modern scuba is an inordinately safe hobby, but if and when something happens, it can mean death. Especially with tec."

"I just compartmentalise. I observe myself being frightened, then tell myself to stop. What happened on the first dive of the expedition at those pinnacles was... I failed to turn it off."

"No. What you failed to do is to listen to your brain and to look after yourself. You were probably heading towards a hypo, which explains most of your behaviour. I think your stress had been brewing for a long time, and what happened on the dive just broke the camel's back. We don't have an endless capacity for enduring pain and fear; it will come and bite us in the arse eventually."

Aware of how sensitive a territory their discussion is heading, John clears his throat. "Lunch?"

"Why not."

John drives them to Ta Frenc, Gozo's best-rated restaurant. _If there ever was an occasion to go there, this is it.  
  
_

______________

  
  
"So, what are you _really_ doing here?" John asks after they've clinked together glasses of Maltese red.

"I thought that maybe you wanted to know that I'm done with James Moriarty. There will be a court case. _My_ court case. Against him."

"You came all the way out here to tell me about that? You could have just phoned me, you know? On my phone?" John laughs tersely, and it dies in his throat when he sees that Sherlock has not taken this as the joke it was intended to be.

He looks nothing short of crestfallen—embarrassed, even. The salt water seems to have irritated the scrape on his cheek. When they'd changed into their wetsuits, John had tried to keep his gaze from lingering on the bruises. Some of them look worryingly new. "I didn't mean–– it's good to see you, honestly!" John hastily offers. "Criminal case or private litigation?"

"Criminal. My brother has… friends in the police and court systems; he was able to influence the timing; I had to lay in the groundwork which would ensure James would be removed from the Foundation — otherwise, our funding would be in jeopardy. He's got the Board wrapped around his finger. Things have to be made public, so he can't bury the story."

"What do you mean, public? I assume such a court case might get reported in the press, but…"

"…but his legions of lawyers might well achieve closed doors and a gag order."

"So… you're _making_ it public? How?"

"I gave an interview to the Irish Times. It will be published tomorrow."

"Wow. Why the Irish?"

"Because that's where the bastard's from," Sherlock pushes the words out from behind clenched teeth.

"That'll put a bee in his bonnet. How are you going to keep him from retaliating?"

"Lestrade turned out to be quite useful. Thanks to him, a thorough audit of the Centre's finances from my tenure has been done by an independent investigator who used to work for Scotland Yard and who is now the head financial fraud investigator for the Bank of England. His credentials are unparalleled and spotless. He never takes private clients — unless they happen to be his poker buddies. Lestrade made his acquaintance during a documentary he made about pyramid schemes, and they discovered a mutual love of gambling and bourbon. He was willing to help out; one might say that the report, now safely in the hands of the Board of the Centre, is my way of shifting from defence to offence. I have also informed the Board that certain private matters of mine may be reported in the press soon and that I will take care to keep the Centre out of it."

"That's pretty bloody clever." _I knew you could solve it._

Sherlock licks his lips, looking slightly nervous. "I–– I didn't mean to mess up your schedule by just showing up," he mutters, and it sounds like a placeholder for some apology he doesn't know how to formulate.

 _An attempt to save face?_ Without even thinking, John reaches out to take his hand. "Hey. I meant what I said: it's great to see you. You've not messed up anything; I love a bit of fun diving; if a gig I'm offered doesn't catch my fancy, I have no trouble declining. I had no plans for this week."

Sherlock doesn't seem satisfied by this.

"Has he left you alone?"

"A restraining order will be sought as part of the proceedings; my brother looked into things, and it turns out he's got priors. Left the country before the conviction was read in an earlier case, and Interpol was after him until the case just mysteriously disappeared. Most likely he'd gone to some Middle Eastern country with no extradition deal with Britain; it would be logical that he'd have such connections since he's in the oil business. That's actually what got him interested in marine survey data and sea archaeology; the information collected by scientists sometimes produces info on prospective oil and gas fields. Plus funding historical research is good PR."

John scoffs. "Not surprised he had an ulterior motive. I worried when you were gone in the morning and Jose-Perry said someone pick you up. I thought that was… _him_ , demonstrating that you couldn't get away from him even on the other side of the world."

"That was my brother. I emailed him the night we… spent together. He thought it best to get me into the UK as fast as he could, using resources Moriarty couldn't trace; he managed to surprise me with how fast he arranged everything. A private flight arriving well before the rest of the team gave us some time to hold, in London, what my brother Mycroft dubbed a war council before I headed back to Oxford with the team. Mycroft does so like to be dramatic."

"So the… um… pawns are in place, then?"

"I would say so, yes."

"And you're here to…"

"Get away from it all. I have no desire to spend the next few weeks dodging reporters and having to fear James trying to contact me, to enforce a conversation."

 _Or worse_. John shudders. _You look like he did manage to have a… conversation after you got back home._

"You're the wild card, John. James doesn't know about you. So I thought… Never mind. I'm not here to impose myself on you." Sherlock dabs his lips with the thick, linen napkin.

The meal is over, but John is _not_ over the fact of whose company he's enjoying. _In for a penny, in for a pound._ "I know you've got a fancy hotel room, but would you like to come back to the mainland with me? To see my flat? Come back to mine _not_ to have sex?" He plucks up the courage to joke.

Sherlock's eyes crinkle into the smile forming tentatively on his lips. To John, he suddenly looks much younger; the shadows of worry etched on his features in Guatemala if not evaporate then at least fade. _It's as though he was hoping I'd ask._

When John had picked him up the morning, he'd been the epitome of fashionable and collected with his polo shirt, aviator shades and grey linen shorts; now, his hair is mussed and wild, a curl John had liberated from underneath his mask as they were getting kitted up is plastered against his forehead by seawater and sweat. John can't help but wonder what he'd look like in the same bed, just woken up. _I didn't get to see that the last time_.

"You live in one of those dreadful tourist areas near the capital, don't you?"

John nods and grabs a piece of bread. "St Julian's."

"Well, seeing as you have this morning introduced me to the best Malta has to offer, perhaps it is time for the worst."

John laughs.

  
  


**Notes for the Chapter:**

> I've put up [some photos and a link to a video of the Blue Hole](https://jbaillier.tumblr.com/post/190712992340/the-blue-hole-at-dwejra-in-gozo-is-one-of-maltas) on my tumblr. As a dive site it is exactly as spectacular as described in this chapter.
> 
> A diver very familiar with Gozo might be able to deduce who Morgan Baron is modelled after.


	14. Safely Ashore

**Notes for the Chapter:**

> If you only watch one thing I have linked to this story, [let it be this](https://www.youtube.com/watch?v=nqF4tLSuleM).
> 
> The adrenaline the guy in the beginning must be feeling when he jumps in and, starting from 0:49 onwards when they drift in the current — that's the thing. That's _everything_. For me, drift diving is crack cocaine injected right into the pleasure centre of the brain in an environment few ever get to experience. Those moments are why I wrote this story and the reason I dive. This final chapter will not involve diving, so I thought we'd say farewell to those scenes at this point through this life-affirming video.
> 
> Thank you all who have commented, cheered me on, loved and despaired over these idiots in wetsuits and hoped for a better tomorrow for them, together. It is now time for the conclusion of Thermocline.

> **_“You can never cross the ocean unless you have the courage to lose sight of the shore.”  
>  _ _—_ _Christopher Columbus_ **

  
After dropping off their tanks at the diving centre, John and Sherlock are driven by Morgan to the ferry terminal. While John gives the Gozo diving veteran a recap of their Guatemalan expedition and listens to Morgan's griping about Maltese bureaucracy, Sherlock sits quietly in the back seat, water bottle in hand and shades on. He's startled when Morgan calls his name out.

"You enjoy your day out with John, then, Mister Holmes?"

"Couldn't have hoped for a better guide," he says and flashes on a cordial smile while removing his shades. "Thank you for making the arrangements."

"With John, all I need to do is tell him where to dive and when. Unlike some of these younger primadonnas, he's not afraid of hard work, always gives a hundred per cent."

"Shut it, you old fool," John chuckles. "You're embarrassing me."

"Malta sun's made me head go soft, you know. They'd lock me up for saying nice things to people back in rainy old England."

"I'm aware of John's many fine qualities," Sherlock comments, and his and John's eyes meet in the rear-view mirror.

  
________________

The sun is setting as the ferry makes its way across the strait between the mainland and Gozo. John had parked next to the Cirkewwa ferry terminal. He'd left his dive gearbox with the ferry attendants, and they recover it once the ferry's car deck has been emptied and the staff can get to the crates in the back.

They roll down the windows of John's banged-up jeep. Sherlock's curls are whipped around by the warm evening breeze. Once they get closer to the capital, streets get busier with tourists wandering around looking for restaurants and locals heading home or to a grocery store after work. As they drive past Mater Dei Hospital, John makes small talk, explaining the island's hyperbaric chamber system. Apart from that, the drive is spent in companionable silence. John wonders when Sherlock had flown in and why he'd picked a hotel on Gozo, but those questions can wait — right now, he just wants to relish the fact that Sherlock is here, with him, in his car. _He'll have to spend the night, won't he, since he'll hardly want to catch a night bus to the ferry?_ John has a sense that Sherlock has not made many plans for this escape-slash-holiday.

They manage to find a parking spot on Triq Il-Karmnu only a block away from John's seaside flat on George Borg Olivier Street, and Sherlock helps him carry his gear. His own had been left with Morgan to be stored until his departure.

They close the door of the flat behind them just as the bells of the Church of Our Lady of Mount Carmel behind sounding from across the small inlet separating St Julian's Bay from Exiles Bay. John gives his guest a very brief tour of the place since there isn't that much to see, after which Sherlock wanders around the living room, picking up and examining the sparse items John has put on the shelves. He's tried not to amass a whole lot of possessions; who knows, when an offer might appear that would take him across the globe for a year or two. The less he'd have to pack up, the better. "Malta is home, but not really _home_ if you know what I mean," he comments sheepishly.

Sherlock peers into a small bottle with a ship inside crafted from cloth and wood. "A trireme. Surprisingly historically accurate."

"Picked that up in Kea where we dived the Britannic."

Sherlock's attention instantly jumps from the bottle to him. "The _Britannic_? How was it?"

Discovered by renowned nautical explorer and documentarist Jacques Cousteau, the wreck of the British WWI hospital ship sunk in 1916 into water 120 metres deep. The largest civilian shipwreck in history, the Britannic was a sister ship of and even larger than Titanic. It sank after hitting a German mine, but there were few casualties since it happened close to the coast, the air and water were warm, and there were plenty of lifeboats available. Only thirty perished.

"One of my best dives. An RAMC Captain who went down with it, John Cropper, was actually a distant relative. We managed to locate his cabin, and I got to recover some of his possessions. The Imperial War Museum's got them now."

"Who did this 'we' include?"

"Just a few tec instructor friends and Simon Mills, a guy who later brought the wreck from the Greek government. Greek authorities weren't being very strict in limiting access since so few people have the qualifications to do it, anyway. Mills bought the wreck for fifteen grand — mainly to protect it from being looted. If you want to dive it now, you need his permission. Our team had a permit from the government, which included bringing artefacts to the surface, which were then presented to the National Historical Museum before they let us export them."

"Have you any footage from the dive?"

"Sure." John starts digging around a drawer below his TV. Mills had sent him the tapes as digitised versions a few years prior.

Soon, they are watching as John, in full tec gear, enters through the massive, gaping hole in the ship's side where the mine explosion had torn through the hull.

"I never was quite aware of enjoying the process of tec diving. It was just a means to an end. Now that I can no longer be a part of that, it's…" Sherlock trails out. "Maybe I feel a loss of certain aspects of it. Diving today made me feel it more acutely than I did back home after the expedition."

"Small submersibles are being used now to explore deep wrecks, and wearable camera systems you can give your team are developing all the time. You'll feel less and less like you've been benched, and if you keep up with improving your hypo situation, regular scuba might well be possible." John wonders if a part the melancholy Sherlock is expressing stems from the stubborn, independent man's petulant anger at being told _no_. Then again, who wouldn't love what they'd seen and experienced together today and feel a bit bitter for losing it, albeit temporarily. _Maybe Sherlock is right, and he had enjoyed some of it — he just hadn't been aware of that until it was taken away._ In the future, he might be able to he can scuba dive within reasonable limits and without entering overhead environments. _Plenty of opportunities in that for a marine archaeologist._

"Now that I can't dive, I do need someone to be my eyes and ears. Preferably with a GoPro; we're experimenting with a direct satellite link that would allow me to follow the dive in real-time."

"Does that mean you'd finally use a radio?"

Sherlock looks thoughtful. "Maybe. There are three projects in development now with the BBC, one of them a documentary series. I would li––" he trails out, swallows, splays his fingers nervously on the coffee table. "I would love to work with you again. I know you enjoy living here, and that you appreciate your professional freedom and the… _hunting grounds_ here," he adds with obvious disdain.

"They're not going anywhere," John dismisses. Something about Sherlock bringing all that up grates on him. "Having to leave Malta never stopped me before. I wouldn't mind another expedition lead by you."

Sherlock nods towards his bed. "Do you mind if I…?" He's been sitting on the floor since John only has one armchair. He'd offered it to his guest, but Sherlock had waved him off and arranged his sprawly limbs on the rug to watch the diving footage.

"No, go ahead," John encourages. "When did you fly in?"

"Two days ago. Haven't been sleeping very well."

"Yeah, no, I'm not surprised."

Sherlock sits down on the bed, and they continue watching the exploration of the wreck in silence. The next time John glances at his companion, he's scooted down to lie on his side on the bed and closed his eyes. By the time the video ends, Sherlock seems to be asleep.

 _The last few weeks must have been so exhausting_ , John thinks. _With the court case and the imminent media storm… and_ _even with the new BBC stuff, Sherlock probably worries about the Centre once the shit hits the fan in the press about Moriarty._

Three hours later, Sherlock is still snoring quietly on the left side of John's bed. John fetches a giant beach blanket he keeps on the balcony and spreads it on him. When the long hand of the clock hits half-past eleven, he slips into bed next to Sherlock, covers himself with just a sheet since the night is warm and the air-conditioning is still broken and drifts off.

  
__________________

  
  
"I must apologise," comes a sleep-hoarse baritone from the kitchen doorway the next morning. "I really didn't mean to monopolise your bed." Sherlock, wrapped in the sheet John had left on the bed after getting up, yawns and rubs at his eyes.

John closes the fridge door that's blocking his view to the man. "Don't worry about it. You looked like you needed the rest." The man had stayed up all night every night on the boat until John had put his foot down had now slept for fourteen hours straight. Sherlock's hair is a curly mess that's sticking up in every direction, and the look he gives John is lethargically bleary.

 _Nobody gets to see him like this_ , John realises. _Well, except… but that's over, now. It has to be_.

"There's coffee and fruit and some _ftira_ ," he says, nodding towards the two-person table by the window. He'd picked the Maltese pastries up less than thirty minutes prior from a hole-in-the-wall shop in the corner; they're the best on the island in his opinion. Flaky pastry filled with fish, meat or vegetables, a _ftira_ is a quick and filling meal.

Sherlock takes the seat offered, arranging the sheet around him so it won't limit his arm movements. "It's not my habit to fall asleep in other people's residences like this. I'm also aware you may have had other plans for yesterday evening."

_Why does he keep offering me an out, providing me with opportunities to tell him to piss off?_

"Nope. No plans. I enjoyed the company. It's not often people stay the night," he says with a smile that appears so easily in Sherlock's company. "Seems a bit, I don't know, beside the point after the fireworks have gone off if you catch my drift."

Sherlock looks like he really doesn't. "Is that truly all you think about? You don't find any worth in intimacy beyond sex? Is that the only framework within which you evaluate human connection — whether your penis was involved?"

"Really not my point," John says tiredly. _He gets so aggressively defensive so easily_. His focus has been on having fun and relationships aren't something he's been longing for, but last night and their night on the boat had been… different in a very good way. He wants Sherlock to know that, but clearly, it's a hard sell. "I meant it when I said I liked that; you, being next to me. Just like on that last night of the trip. I don't judge you, Sherlock. If anything, I find your approach…" he tries to search for a word, "…refreshing."

"Sounds condescending." Sherlock's long fingers snatch a _ftira_ off the plate.

John wishes he was better at talking about these bloody things. He'd woken up briefly in the middle of the night and just listened to the sound of Sherlock's breathing, feeling an odd pride swell in him for being the one who'd managed to facilitate a restful night for the haunted man. He'd been tempted to reach out, to shift a curl off a brow, to stroke an arm, to press himself to Sherlock's back and hold him, and he'd been surprised to find he wasn't aroused. He didn't _want_ the way he usually wanted; no, this was different. Somehow, the familiar white noise of longing in his bones was being fulfilled just by Sherlock's proximity. It wasn't urgent and compulsive such as the desire he felt with those he'd brought to his bed before. It was… comfortable. Comfor _ting_ , even. He hadn't wished for more at that moment — he was content with what he had. He felt lucky, privileged in a way none of his passings-in-the-night in the last few years had brought on.

He shrugs. "Maybe I need some new definitions, then. I'm sure a man of your verbal prowess can help. All I know is that I'm happy you're here, as long as you want to stay."

"I don't have a ticket booked back yet. I will go back as I must; I have my duties with the Centre, of course, but there is no telling how long it will take until the media storm blows over. I would prefer to… not be in England while that happens. My testimony has been taped beforehand; there's no reason for me to appear in court. They granted me _special court measures_ ," he phrases with what sounds like self-disgust.

"There's no reason for you to have to face this creep ever again. It's good that they offered that to you. You've got a good lawyer?"

"I am borrowing my brother's legal team, yes."

"Good, that's… good."

"I was reluctant to ask for his help. He… he'd heard rumours. About Moriarty. He tried to warn me in the early days of James' involvement with me, in fact. I had no desire to hear Mycroft's told-you-sos. He can act so snidely superior."

The edge of John's mouth twitches up a bit. _A bit like his little brother?_ " What does he do? How would he know the guy?"

"Mycroft occupies what he calls a minor position in the cogs of the government. Gives him access to closed circles. In those circles, any scandal can be killed, and silence bought. He may have brokered such deals, for all I know. Apparently, Moriarty is a return customer if not for him, then some others who have power over the media. That was another reason I went to the Irish press. The people who have assisted Moriarty in getting away with… _things_ have less influence there."

"You think he has other v–– exes?" John corrects. _Sherlock wouldn't want to be called a victim, would he? No, he's got himself out of this. If anything, he's a survivor._

"It's likely. I do wonder how they managed to… leave."

"So, your brother told you getting involved with Moriarty wasn't a good idea. Still, did it really have to go this far before you'd go to him?"

"I didn't want to involve him because he's been lecturing me for years that in order for someone to put up with me, I'd have to make concessions, compromises. As it turns out, this is not what he meant. I've never quite seen him so… apologetically concerned." Sherlock grimaces. "His pity leaves a particularly vile aftertaste."

Sherlock puts down his pastry and licks the tips of his greasy fingers, which John watches with rapt attention.

His shoulders deflate, and he sighs. "What is this, John? What _are_ we?"

"I thought you didn't care much about labels and definitions."

"You seem to need one in order to operate in this relationship."

Sherlock using the R-word should make John splutter in protest since he's spent years avoiding ending up in one. Yet this time, it brings on a flutter in his guts he quite enjoys. "Do you have any suggestions?"

"I would like to start out as friends. I cannot promise more, but I would perhaps be amenable to some exploration."

 _He's not just talking about filming shipwrecks with the BBC,_ John realises. "Sherlock–– I hope you're not saying that because you think I have expectations."

Sherlock schools his disappointment into nonchalance. He's gripping his water glass hard, fingertips drumming the glass surface nervously. "I understand if what I am willing to give isn't what you're looking for. It's clearly not for you, being without regular release––"

John encloses his fidgeting fingers in his hand, covering them on the glass. "I know that life, and I've enjoyed it for twenty years. But here I am, living alone, and one day it'll probably start getting pretty damned lonely. Maybe it's time to… explore something different."

"I have no interest in being your experiment."

"Not what I meant. What I was saying that maybe it's time for something that might last. And I know those things aren't built on sex. It can be a part of that, but I don't want you to think you're the only one who has to stretch their boundaries here. I never slept with anyone who hesitated, never anyone who didn't want it as I wanted it. I just never knew what to do with them the next morning; maybe that's something _I_ need to learn. The last thing I'd want is to pressure you to anything. I know talking about such stuff so soon after _James––_ " if pity is a flavour Sherlock hates, then this guy's name feels like acid on John's tongue, "––the timing is not good. But I can't not say it, Sherlock."

"Say what?"

There's a question in Sherlock's eyes that doesn't need to be spoken out loud. _Would you know what to do with_ me _the next morning?_

The next morning after… _what_? John wonders. Then, he realises he doesn't have to know. Maybe it would be a morning after they had just slept in the same bed, maybe entangled together, maybe not. Maybe having kissed goodnight, maybe not. For the first time in twenty years, John doesn't know what the rules are, what to expect from someone he has chosen to be intimate with. Suddenly, that word has gained a thousand new meanings besides the old, simple, stale one of sex.

He doesn't know what's going to happen, and he's astounded that it excites him more than any promise of orgasms.

Sherlock is still looking at him expectantly. "Say what, John?"

"That I want you to be here. What do you want to do today? I haven't got anything on," he side-rails the topic. _This is so fucking hard._ "Could do some sightseeing, find a nice secluded cove somewhere."

"Not keen on anything involving lots of people. I came here to avoid attention from everyone except you."

 _Except you_. Those two words make John's heart somersault a little. _Stop looking for a definition, for decisions, for something certain or predictable. Just be with him_ , he tells himself.

"Right," he says, standing up and switching off the coffee maker. "We need wine, water, some food, and I know just the place for a day trip."

____________  
  


  
There is another chapel dedicated to Our Lady of Mount Carmel in Il-Fawwara, rarely if ever visited by tourists. A forty-five-minute walk from the car park meanders down to the southwestern coast. Sherlock had not brought hiking boots, but his boating shoes are fine to navigate the dry, worn path down to a narrow sandy beach wedged between worn limestone cliffs. Red rocks rounded by water and wind over thousands of years line the white sand like a giant's broken pearl chain.

"You have to know some locals to find a beach that's not all packed with people. Sandy beaches aren't very common here," John explains.

"Lucky me, then, to be taken to your special spot." Sherlock is standing close to the water's edge, arms crossed. His statement is joyless.

"Hey," John says gently, putting down the basket he'd been carrying. He carefully, gently wraps an arm around Sherlock's shoulders and is relieved to feel him lean against his chest. "What's going on?"

"It's frustrating not to know how things are advancing. I've tried not to read the papers; I hardly want to see my name plastered all across them, but it's hard to not be on top of things. It's not all just going to go away by the time I go back, is it?"

"I'm long overdue for a trip back. What if I came home with you?"

Sherlock regards him with a sad expression. "I don't want you on James' radar, and frankly, that's a bit too much at this stage, John."

"Not like _that_ ," John corrects. It seems they are both guilty for reading too much into things and not knowing how to interpret the other. "I just want you to have someone you can talk to."

"Why you?" Sherlock asks, genuinely perplexed. John realises he isn't asking him but asking _himself_. "You are everything I never understood, you represent all the things I have dismissed as pointless and base, things I thought I should rise above."

"Thanks," John chuckles. "Nice view from up there on that horse?"

Sherlock leans his temple against John's shoulder. "It was infuriating, the way you kept returning to my thoughts on the boat. Intolerably distracting."

"I've kept thinking of you, too." John takes his hand and leads him down to a pair of smooth rocks perfect for sitting on. He digs out the bottle of rosé they'd bought from a supermarket. It's hardly cold but should still taste alright. Plastic cups are not exactly the height of romance, but it seems that not doing things the usual way is the staple of the two of them. _The hallmark of John and Sherlock_.

"I have baggage, John. I can't promise I won't be reminded of _him_ — a lot. And I can't promise you won't notice. The lessons he thought he could teach me were the wrong ones, and I don't know if further education can unravel them."

"I don't want to change you. If Moriarty thought he could do that, he was looking at the whole thing from the wrong angle. If he wanted a different you, he didn't want _you_."

 _I don't care if you have baggage. I don't care about any of it. I just want to be with you_.

"He said I was his _project_ , just like the Foundation was. He took what showed promise and changed it to his liking."

"Well, I'm glad you're proving him otherwise."

"I doubt I can change his thinking any more than he could change the fundamentals of mine."

_Yeah, I doubt sadistic arseholes are good at mending things and becoming nicer. No wonder Sherlock bites people's heads off when the conversation turns to sex. It's got to be one hell of a mess to unravel that Moriarty's put in his head of what it should mean to be with someone._

Sherlock rises to his feet and moves from the shadow to sit on the sunlit sand. John joins him, placing their glasses on a small rock. He scoots closer, pressing his lips to Sherlock's sweaty neck. He does it not with the intention to make it foreplay, but just because the rush of affection he feels needs an outlet. "Is this alright?"

"I will tell you if you do something I don't enjoy. I'm not the way I am because of him, and I won't break into pieces from such things, John. If I change my mind about something, I am capable of saying no."

"I know." Smiling, John dares to press another kiss to his neck, wraps his arms tight around Sherlock. _I'm never nervous like this. Look what you bloody do to me, Sherlock Holmes_. He almost hopes for the man to pick up on it so he'd feel less wrong-footed about all the physical stuff. "You have to be honest with me. I don't want anything you don't want."

Sherlock is right in that he is analysing and second-guessing, trying to stay carefully attuned. He has to get close by keeping his distance, to approach slowly to ensure the other is not just grinning and bearing it.

"I detest that this is now something you're constantly trying to analyse when it comes to getting to know me. That's how people always see it: like I'm some exotic creature to be housetrained." He leans forward as if to pull away and stand up. "Maybe I shouldn't have come here."

John rests his palms on his shoulders and is relieved when this is enough to keep Sherlock from pulling away. "I'm glad you came. You have no idea how glad."

"And that is precisely the problem. I've come here with no intentions, no promises, with nothing to offer. I'm just imposing on your time and your hospitality. It's obvious you're interested, it's obvious you want… things, and that's what he always accused me of, pretending something was on offer by not denying it, told me I was a damned tease. I was surprised you didn't lose interest after I rejected you on that first night. I should have left things at that, having made the right decision then."

John runs a nervous hand through his hair. How does he even begin to dismantle all those lies and assumptions? "Was it the wrong decision, becoming friends? Was it the wrong decision, spending that final night together? I didn't feel deprived of anything then, Sherlock. If anything, it was the nicest night I've had in years. Felt good. Comfortable. Wasn't it like that for you?"

"It was, and _that's why I'm here_!" Frustration is straining Sherlock's vocal cords.

"I want to be here; you want to be here together. Maybe not analyse it any further?" _God knows I've tried to pick it apart, and it doesn't work._

Sherlock settles back against his chest, and John inhales the scent of his sun-warm hair. He has a nape curl which coils every which way and bounces when his head moves. He has soft, almost translucent hairs on his pale, creamy-soft skin under his halo of dark curls which stand up as John lets his breath ghost there. _Funny, how I never used to notice these things on people. I guess I never stopped to look, being on a rush to get on with things in bed._

"I want to know _everything_ about you, and this just happens to be an unusual thing we've got," he reassures Sherlock. "I don't know the rules here, and it's bloody refreshing. You've knocked me off balance, which you should take as a compliment: I kind of find everything about you confusing and interesting."

"Confusing is somehow good, all of a sudden?"

John exhales thoughtfully, leans his forehead on the luscious curls in front of him. "I thought I had my life all worked out, but then you barged into it."

"I don't _barge––"_

John laughs. "I thought I knew how it all worked, sex and all, and maybe, _maybe_ it was getting a bit paint-by-numbers. You opened a door I didn't know existed."

He feels Sherlock's shoulders relax a little. "Oh."

________________

Sherlock doesn't go back to his hotel that night. There is no discussion about it, he simply does not request John to take him back. They stay up late, talking over another bottle of wine. When conversation wanes and yawning begins, clothes are discarded down to underwear, and they slip into John's bed just as they had been the night before: John on the left, Sherlock on the right.

John is content just to be, to relish the presence of another person in the room. He's close to dozing off, when an arm reaches across his torso, pulls him closer.

"Can we just… _this_ ," Sherlock explains, sounding frustrated.

"'Course we can. Whatever you want, we can," John whispers. Maybe it is good that they are unlikely ever to reach John's hard limits. It means Sherlock can approach him at his own pace without fearing rejection, without fearing there's something wrong with what he wants or doesn't want.

He clasps Sherlock's hand in his own, and rests them on his hip, slips his own shorter fingers between long, lithe ones. It's dark, but he can make out the boundaries of Sherlock's body and where his hair fans out on the pillow.

"Just this," Sherlock whispers.

John can't tell if it's a question, but he answers with a squeeze of his hand all the same.

_______________

In the early hours of the morning, something makes John surface from sleep. After a moment of disorientation, he can make out Sherlock's dark form against the moonlight streaming through the window. He's sitting up.

"You okay?" John asks.

There's no reply.

"Did you…" John swallows, lets intuition take over, "…have a nightmare?"

Sherlock mutters something, then slips out of bed. Soon John spots the glowing red spot of a cigarette as he settles into a chair to smoke. John doesn't like people doing that in his flat, but this once he doesn't hesitate to let it slide.

John gathers himself up off the bed and goes to sit on the coffee table, facing Sherlock as he leans his elbows on his knees. "What's wrong?" He asks bluntly.

"You'd moved to the other side of the bed, and I wanted…" he mutters something John can't quite decipher, "––but you would have woken up, perhaps assumed too much about where I wanted things to go."

It's frustrating, how wary Sherlock is of him physically, but John reminds him it's also entirely logical. "Do you often assume you have to take over thinking for other people?" He asks quietly.

"I find people often don't do that for themselves."

John's lip quirks up. "Maybe your problem's more the opposite. That you overthink things."

"You keep making promises of no expectations, but in the light of your lifestyle, I find that hard to believe."

"Can people change, do you think, Sherlock?"

"Why would anyone do that for me?"

John's heart clenches a little bit. _That he would have so little confidence about why anyone would want him. No wonder that creep put him under some fucking spell._ He watches the younger man inhale deep, luxurious drags from the cigarette until it's just a stub. John then grabs a used tea mug from the table and offers it as a makeshift ashtray; Sherlock drops it in.

"Do you want to come back to bed?" John asks.

"Yes."

John spreads the sheet over them; it's a very warm night. In his many years of spending time in bed with other people, he cannot remember it ever feeling this naked or this brittle. Emotional attachment, relationship, all that used to make him want to run, but what's there to run away from in Sherlock? John wants him close, wants to protect him with a fierceness that is as novel as it is intense.

They're facing each other, their facial features only barely visible in the low light. "What did you need?" John whispers. "Before, when you woke up? What did you want to do?"

Hesitantly, Sherlock scoots closer, turns onto his side — nearly on his stomach, and rests his cheek where the front of John's shoulder meets his chest. John reaches out to stroke his hair down towards his neck — but when he reaches the shoulder, Sherlock tenses.

"Too much?"

"No, it's… it's just sore?"

John's brows dip into a V in confusion. He pushes Sherlock's head away from him a bit as he turns it and reaches out his other hand to click on the reading light.

There's a dark bruise underneath the curls and skin close to his hairline. Sherlock only barely aborts a hiss when John presses on it with his fingertips. The sheet has slipped off Sherlock's hip; his boxers are riding low, and there's a row of yellowish-green, fingertip-shapes bruises on his hip which cannot be older than a few weeks. "You went _back_ to him?"

John releases his gentle grip on the back of Sherlock's head.

"I saw him once, to make sure he didn't suspect anything."

"But this is… it needs to be fucking documented!"

"It was," Sherlock replies in a calm, collected, distant tone. "The photographs you took did not include the damage from my last encounter, so the police insisted on an exam and documentation by their own photographer with the forensic physician, as requested by the detective. If I was to go to the press, there needed to be tangible evidence so that Moriarty's lawyers couldn't tear the case to shreds before it even got to court."

"You used yourself as _bait_?" Perhaps that's not the word, and it isn't really entrapment, but it's the middle of the night and John is severely upset by his discovery.

There's a shudder of a shrug. "It's just pain. It doesn't mean anything."

_I think it means a hell of a lot, but maybe you're not ready to admit that. Would you be here if it didn't?_

John realises that it's the most important question, really: what happens when this blows over? Sherlock came to him because he needed someone, a place, a safe haven. That makes John want to be immensely careful about not reading too much into what goes on between them. But why choose him of all people? He'd mentioned a brother who was helping him with the court case. Why not go to family?

 _He's in your bed_ , John tells himself. _That has to mean something, too_.

Sherlock shifts a little, presses himself closer to John, splaying the fingers of his right hand on John's chest on top of the sheet.

 _You wanted this, just this, and instead, that arsehole just… what? Fucked you instead?_ Suddenly, John feels a tremendous need to make sure Sherlock knows that is not him. That it will never be him. That respect is what he feels more for Sherlock than some animalistic lust.

"I was chatting someone up a few days before you showed up," John tells him. "But I kept… this is going to sound mad; I kept hearing _you_ in my head. Things I imagined you would have commented like some bloody narrator of a nature documentary. _Here we see John Watson exhibiting his usual mating behaviour––_ "

He feels Sherlock's belly clench against his chest as he chuckles quietly.

"I'll admit that you've been in my thoughts occasionally."

"Only occasionally?" John teases.

"That first night… you may assume I shot you down because nothing about the offer enticed. That premise is patently wrong because I have _eyes_ , John," he insists. "No, I did not want your company on that night, and later I would not encourage your interest because I just knew it would be too complicated. I would have had to provide a lengthy explanation, and you would have been disappointed. But that doesn't mean I didn't want your company later, once I spent more time with you."

"You haven't disappointed me. What you've done is make me think differently."

"On the occasions when the fact that I am different from the norm has been underlined, it has never been in a positive light."

"Let this be the first time, then. You have to understand this: I'm not James. Hurting people is not what I'm about."

He presses a kiss to the crown of Sherlock's hair, strokes a gentle hand down his long back muscles. _He's so beautiful._ John realises he'd never done this before, just slowed down to appreciate the way someone looked and felt under his hands. He'd chased a high, a release, and when that was gone, he assumed the next reward would equal a second orgasm.

 _It can't ever be about teaching him to enjoy sex. Maybe that's what that fuckwit thought he was doing_. _It can't ever be that, because Sherlock doesn't need to change. Not for me._

 _But maybe I do._ It doesn't mean he doesn't want Sherlock — he desires the man in a way that makes the hairs of the back of his neck rise up and makes his skin prickle with anticipation. He _wants_ , but it's interspersed with a different longing — that Sherlock would want to be with him, and that can't happen unless John respects who he is.

"I will never hurt you. Not ever," he whispers and feels a nod against his chest. "Stay. Stay as long as you need, Sherlock."  
  
  


### ———The End———  
  
  


**Notes for the Chapter:**

> I am in great debt to a special secret beta who was willing to reflect on some very personal things so that Sherlock's sexuality could be treated with the attention to detail and respect it deserved.
> 
> Ghajn Barrani on Gozo served as the blueprint for the beach. [Images 1](https://www.chevron.co.uk/blog/ghajn-barrani-trekking-for-the-adventurous/). [Images 2](https://www.visitgozo.com/where-to-go-in-gozo/beaches/ghajn-barrani/). 
> 
> [Info on the Britannic](https://eandt.theiet.org/content/articles/2016/09/exploring-the-britannic-wreck-titanics-sister-ship/). Diving footage from the wreck: [Video 1](https://www.youtube.com/watch?v=L5XLFvLjwA4). [Video 2](https://www.youtube.com/watch?v=onQNvS1fPnw).
> 
> What's next in the catalogue of my works? Well, on February the 17th the first chapter of the podfic for [Proving A Point](https://archiveofourown.org/works/18826798) will see the light! After that, I believe I have adventures planned for my doctor boys.

**Author's Note:**

> Mostly betaed by 7PercentSolution. Any plotholes should be blamed solely upon the JBall.


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